ci: add ability to rc and graduate a release

.github/workflows/release-please.yml

@@ -5,6 +5,17 @@ on:
     branches:
       - main
   workflow_dispatch:
+    inputs:
+      release-candidate:
+        description: 'Cut a release-candidate (prerelease) instead of a normal release.'
+        type: boolean
+        required: false
+        default: false
+      graduate:
+        description: 'Graduate the current RC to its final version (drops the -rc.N suffix).'
+        type: boolean
+        required: false
+        default: false
 
 env:
   RELEASE_BRANCH: release-please--branches--main--components--github-actions-magento2
@@ -17,10 +28,34 @@ jobs:
     outputs:
       releases_created: ${{ steps.release.outputs.releases_created }}
     steps:
+      - name: Reject conflicting inputs
+        if: inputs.release-candidate && inputs.graduate
+        run: |
+          echo "::error::release-candidate and graduate are mutually exclusive — pick one."
+          exit 1
+
+      - uses: actions/checkout@v6
+        if: inputs.graduate
+
+      - name: Compute graduate version
+        id: graduate
+        if: inputs.graduate
+        run: |
+          CURRENT=$(jq -r '."."' .release-please-manifest.json)
+          if [[ "$CURRENT" != *-* ]]; then
+            echo "::error::Manifest version $CURRENT has no prerelease suffix to graduate from."
+            exit 1
+          fi
+          GRADUATED="${CURRENT%%-*}"
+          echo "Graduating $CURRENT -> $GRADUATED"
+          echo "VERSION=${GRADUATED}" >> $GITHUB_OUTPUT
+
       - id: release
         uses: googleapis/release-please-action@v4
         with:
           token: ${{ secrets.GRAYCORE_GITHUB_TOKEN }}
+          versioning-strategy: ${{ inputs.release-candidate && 'prerelease' || '' }}
+          release-as: ${{ steps.graduate.outputs.VERSION || '' }}
 
       - name: Check if release branch exists
         id: branch-check