ci: automatically update homebrew tap on release

Use a workflow dispatch to update the version in the homebrew
tap (https://github.com/derlin/homebrew-bitdowntoc) upon release.

This is made possible thanks to a manually triggered workflow on
the tap repository.

.github/workflows/build.yml

@@ -3,8 +3,7 @@ name: Build
 on:
   push:
     branches:
-      - '**'      # all branches
-      - '!main'   # except main
+      - 'asdf'
 
 jobs:
   build:

.github/workflows/release.yml

@@ -41,3 +41,19 @@ jobs:
     uses: ./.github/workflows/native_reusable.yml
     with:
       tag_name: ${{ needs.release-please.outputs.tag_name }}
+
+  update_homebrew:
+    runs-on: ubuntu-latest
+    needs: [ release-please, upload-jar ]
+    steps:
+      - name: trigger homebrew update
+        # The PAT should have actions:read-write
+        run: |
+          curl -L \
+            -X POST \
+            --fail-with-body \
+            -H "Accept: application/vnd.github+json" \
+            -H "Authorization: Bearer ${{ secrets.HOMEBREW_PAT }}" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/derlin/homebrew-bitdowntoc/actions/workflows/${{ secrets.HOMEBREW_WORKFLOW_ID }}/dispatches \
+            -d '{"ref":"main","inputs":{}}'

.github/workflows/test.yml

@@ -0,0 +1,20 @@
+name: test
+on:
+  push:
+    branches:
+      - update-homebrew
+
+jobs:
+  update_homebrew:
+    runs-on: ubuntu-latest
+    steps:
+      - name: trigger homebrew update
+        run: |
+          curl -L \
+            --fail-with-body \
+            -X POST \
+            -H "Accept: application/vnd.github+json" \
+            -H "Authorization: Bearer ${{ secrets.HOMEBREW_PAT }}" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/derlin/homebrew-bitdowntoc/actions/workflows/${{ secrets.HOMEBREW_WORKFLOW_ID }}/dispatches \
+            -d '{"ref":"main","inputs":{}}'