feat(CI): Add post-release workflow

Starts a new dev version after we sucessfully released the gem.

Signed-off-by: Thomas von Deyen <thomas@vondeyen.com>

Author: tvdeyen

.github/workflows/post-release.yml

@@ -0,0 +1,56 @@
+name: Post Release
+
+on:
+  workflow_run:
+    workflows: ["Publish Release"]
+    types:
+      - completed
+
+jobs:
+  bump-dev-version:
+    if: github.event.workflow_run.conclusion == 'success'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Generate token
+        id: generate-token
+        uses: actions/create-github-app-token@v1
+        with:
+          app-id: ${{ vars.ALCHEMY_BOT_APP_ID }}
+          private-key: ${{ secrets.ALCHEMY_BOT_APP_PRIVATE_KEY }}
+
+      - uses: actions/checkout@v4
+        with:
+          token: ${{ steps.generate-token.outputs.token }}
+          ref: main
+
+      - name: Calculate next dev version
+        id: version
+        run: |
+          # Read current version
+          CURRENT=$(grep VERSION lib/alchemy/solidus/version.rb | sed 's/.*"\(.*\)".*/\1/')
+          echo "Current version: $CURRENT"
+
+          # Split into major.minor.patch
+          IFS='.' read -r MAJOR MINOR PATCH <<< "$CURRENT"
+
+          # Bump minor version and add .dev suffix
+          MINOR=$((MINOR + 1))
+          NEW_VERSION="$MAJOR.$MINOR.0.dev"
+          echo "New dev version: $NEW_VERSION"
+          echo "version=$NEW_VERSION" >> $GITHUB_OUTPUT
+
+      - name: Configure git
+        run: |
+          git config user.name "alchemycms-bot"
+          git config user.email "alchemycms-bot@users.noreply.github.com"
+
+      - name: Bump to dev version
+        run: |
+          sed -i 's/VERSION = "[^"]*"/VERSION = "${{ steps.version.outputs.version }}"/' lib/alchemy/solidus/version.rb
+
+      - name: Commit and push
+        run: |
+          git add lib/alchemy/solidus/version.rb
+          git commit -m "Start development of version ${{ steps.version.outputs.version }}"
+          git push origin main