chore: Run single Ubuntu build if there are no code changes

.github/workflows/main.yml

@@ -284,9 +284,11 @@ jobs:
       contents: read
     steps:
     - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      if: github.event_name == 'push' || needs.changes.outputs.code == 'true' || (matrix.umask == '022' && matrix.test-index == 0)
       with:
         fetch-depth: 0
     - uses: ./.github/actions/setup-go
+      if: github.event_name == 'push' || needs.changes.outputs.code == 'true' || (matrix.umask == '022' && matrix.test-index == 0)
       with:
         go-version: ${{ env.GO_VERSION }}
     - name: install-age
@@ -297,15 +299,18 @@ jobs:
         sudo install -m 755 age/age /usr/local/bin
         sudo install -m 755 age/age-keygen /usr/local/bin
     - name: install-rage
+      if: github.event_name == 'push' || needs.changes.outputs.code == 'true'
       run: |
         cd "$(mktemp -d)"
         curl -fsSL "https://github.com/str4d/rage/releases/download/v${RAGE_VERSION}/rage-v${RAGE_VERSION}-x86_64-linux.tar.gz" | tar xzf -
         sudo install -m 755 rage/rage /usr/local/bin
         sudo install -m 755 rage/rage-keygen /usr/local/bin
     - name: build
+      if: github.event_name == 'push' || needs.changes.outputs.code == 'true' || (matrix.umask == '022' && matrix.test-index == 0)
       run: |
         go build -v ./...
     - name: run
+      if: github.event_name == 'push' || needs.changes.outputs.code == 'true' || (matrix.umask == '022' && matrix.test-index == 0)
       run: |
         go run . --version
     - name: test-umask-${{ matrix.umask }}