Add release workflow

.github/actions/create-github-release/action.yml

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+name: Create GitHub Release
+description: Create the release on GitHub with a changelog
+inputs:
+  milestone:
+    description: Name of the GitHub milestone for which a release will be created
+    required: true
+  token:
+    description: Token to use for authentication with GitHub
+    required: true
+runs:
+  using: composite
+  steps:
+    - name: Generate Changelog
+      uses: spring-io/github-changelog-generator@052892c62af51f8af87a9da6de55e70864b7df12
+      with:
+        milestone: ${{ inputs.milestone }}
+        token: ${{ inputs.token }}
+        config-file: .github/actions/create-github-release/changelog-generator.yml
+    - name: Create GitHub Release
+      env:
+        GITHUB_TOKEN: ${{ inputs.token }}
+      shell: bash
+      run: gh release create ${{ format('v{0}', inputs.milestone) }} --notes-file changelog.md

.github/actions/create-github-release/changelog-generator.yml

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+changelog:
+  repository: spring-io/initializr
+  sections:
+    - title: ":star: New Features"
+      labels:
+        - "type: enhancement"
+    - title: ":lady_beetle: Bug Fixes"
+      labels:
+        - "type: bug"
+        - "type: regression"
+    - title: ":notebook_with_decorative_cover: Documentation"
+      labels:
+        - "type: documentation"
+    - title: ":hammer: Dependency Upgrades"
+      sort: "title"
+      labels:
+        - "type: dependency-upgrade"

.github/actions/sync-to-maven-central/action.yml

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+name: Sync to Maven Central
+description: Syncs a release to Maven Central and waits for it to be available for use
+inputs:
+  jfrog-cli-config-token:
+    description: 'Config token for the JFrog CLI'
+    required: true
+  initializr-version:
+    description: 'The version of Initializr that is being synced to Central'
+    required: true
+  ossrh-s01-token-username:
+    description: 'Username for authentication with s01.oss.sonatype.org'
+    required: true
+  ossrh-s01-token-password:
+    description: 'Password for authentication with s01.oss.sonatype.org'
+    required: true
+  ossrh-s01-staging-profile:
+    description: 'Staging profile to use when syncing to Central'
+    required: true
+runs:
+  using: composite
+  steps:
+    - name: Set Up JFrog CLI
+      uses: jfrog/setup-jfrog-cli@d82fe26823e1f25529250895d5673f65b02af085 # v4.0.1
+      env:
+        JF_ENV_SPRING: ${{ inputs.jfrog-cli-config-token }}
+    - name: Download Release Artifacts
+      shell: bash
+      run: jf rt download --spec ${{ format('{0}/artifacts.spec', github.action_path) }} --spec-vars 'buildName=${{ format('initializr-{0}', inputs.initializr-version) }};buildNumber=${{ github.run_number }}'
+    - name: Sync
+      uses: spring-io/nexus-sync-action@42477a2230a2f694f9eaa4643fa9e76b99b7ab84 # v0.0.1
+      with:
+        username: ${{ inputs.ossrh-s01-token-username }}
+        password: ${{ inputs.ossrh-s01-token-password }}
+        staging-profile-name: ${{ inputs.ossrh-s01-staging-profile }}
+        create: true
+        upload: true
+        close: true
+        release: true
+        generate-checksums: true
+    - name: Await
+      shell: bash
+      run: |
+        url=${{ format('https://repo.maven.apache.org/maven2/io/spring/initializr/initializr-generator/{0}/initializr-generator-{0}.jar', inputs.initializr-version) }}
+        echo "Waiting for $url"
+        until curl --fail --head --silent $url > /dev/null
+        do
+          echo "."
+          sleep 60
+        done
+        echo "$url is available"

.github/actions/sync-to-maven-central/artifacts.spec

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+{
+  "files": [
+    {
+      "aql": {
+        "items.find": {
+          "$and": [
+            {
+              "@build.name": "${buildName}",
+              "@build.number": "${buildNumber}"
+            }
+          ]
+        }
+      },
+      "target": "nexus/"
+    }
+  ]
+}

.github/workflows/release.yml

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+name: Release
+on:
+  push:
+    tags:
+      - v[0-9]+.[0-9]+.[0-9]+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+jobs:
+  build-and-stage-release:
+    if: ${{ github.repository == 'spring-io/initializr' }}
+    name: Build and Stage Release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out
+        uses: actions/checkout@v4
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          java-version: '17'
+          distribution: 'liberica'
+          cache: 'maven'
+      - name: Maven deploy
+        run: ./mvnw --no-transfer-progress --batch-mode --update-snapshots -DaltDeploymentRepository=local::file:./maven-repo/ clean deploy -Pfull
+      - name: Read version
+        id: read-version
+        shell: bash
+        run: | 
+          version=$(sed -n 's/^.*<revision>\(.*\)<\/revision>.*$/\1/p' pom.xml)
+          echo "Version is $version"
+          echo "version=$version" >> $GITHUB_OUTPUT
+      - name: Stage Release
+        uses: spring-io/artifactory-deploy-action@26bbe925a75f4f863e1e529e85be2d0093cac116 # v0.0.1
+        with:
+          build-name: ${{ format('initializr-{0}', steps.read-version.outputs.version)}}
+          folder: 'maven-repo'
+          password: ${{ secrets.ARTIFACTORY_PASSWORD }}
+          repository: 'libs-staging-local'
+          signing-key: ${{ secrets.GPG_PRIVATE_KEY }}
+          signing-passphrase: ${{ secrets.GPG_PASSPHRASE }}
+          uri: 'https://repo.spring.io'
+          username: ${{ secrets.ARTIFACTORY_USERNAME }}
+    outputs:
+      version: ${{ steps.read-version.outputs.version }}
+  sync-to-maven-central:
+    name: Sync to Maven Central
+    needs:
+      - build-and-stage-release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out
+        uses: actions/checkout@v4
+      - name: Sync to Maven Central
+        uses: ./.github/actions/sync-to-maven-central
+        with:
+          jfrog-cli-config-token: ${{ secrets.JF_ARTIFACTORY_SPRING }}
+          ossrh-s01-staging-profile: ${{ secrets.OSSRH_S01_STAGING_PROFILE }}
+          ossrh-s01-token-password: ${{ secrets.OSSRH_S01_TOKEN_PASSWORD }}
+          ossrh-s01-token-username: ${{ secrets.OSSRH_S01_TOKEN_USERNAME }}
+          initializr-version: ${{ needs.build-and-stage-release.outputs.version }}
+  promote-release:
+    name: Promote Release
+    needs:
+      - build-and-stage-release
+      - sync-to-maven-central
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up JFrog CLI
+        uses: jfrog/setup-jfrog-cli@d82fe26823e1f25529250895d5673f65b02af085 # v4.0.1
+        env:
+          JF_ENV_SPRING: ${{ secrets.JF_ARTIFACTORY_SPRING }}
+      - name: Promote build
+        run: jfrog rt build-promote ${{ format('initializr-{0}', needs.build-and-stage-release.outputs.version)}} ${{ github.run_number }} libs-release-local
+  create-github-release:
+    name: Create GitHub Release
+    needs:
+      - build-and-stage-release
+      - promote-release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out
+        uses: actions/checkout@v4
+      - name: Create GitHub Release
+        uses: ./.github/actions/create-github-release
+        with:
+          milestone: ${{ needs.build-and-stage-release.outputs.version }}
+          token: ${{ secrets.GH_ACTIONS_REPO_TOKEN }}