Prepare release automation (#1200)

* Prepare release automation

Adds automation to prepare a classic buildpack release. See heroku/languages-github-actions#183

* Remove "Buildpack" from workflow name
* Always use Title Case for workflow display names

---------

Co-authored-by: Ed Morley <501702+edmorley@users.noreply.github.com>

.github/workflows/hatchet_app_cleaner.yml

@@ -1,4 +1,4 @@
-name: Hatchet app cleaner
+name: Hatchet App Cleaner
 
 on:
   #schedule:

.github/workflows/hatchet_app_cleaner.yml.orig

@@ -0,0 +1,31 @@
+name: Hatchet app cleaner
+
+on:
+  #schedule:
+    # Daily at 6am UTC.
+  #  - cron: "0 6 * * *"
+  # Allow the workflow to be manually triggered too.
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  hatchet-app-cleaner:
+    runs-on: ubuntu-latest
+    env:
+      HEROKU_API_KEY: ${{ secrets.HEROKU_API_KEY }}
+      HEROKU_API_USER: ${{ secrets.HEROKU_API_USER }}
+      HEROKU_DISABLE_AUTOUPDATE: 1
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Install Ruby and dependencies
+        uses: ruby/setup-ruby@v1
+        with:
+          bundler-cache: true
+          ruby-version: "2.7"
+      - name: Run Hatchet destroy
+        # Only apps older than 10 minutes are destroyed, to ensure that any
+        # in progress CI runs are not interrupted.
+        run: bundle exec hatchet destroy --older-than 10

.github/workflows/prepare_release.yml

@@ -0,0 +1,9 @@
+name: Prepare Release
+
+on:
+  workflow_dispatch:
+
+jobs:
+  prepare-release:
+    uses: heroku/languages-github-actions/.github/workflows/_classic-buildpack-prepare-release.yml@latest
+    secrets: inherit