Add workflow_dispatch trigger to release preparation

Author: gastaldi

.github/workflows/release-prepare.yml

@@ -1,21 +1,22 @@
 name: Quarkiverse Prepare Release
 
 on:
+  workflow_dispatch:
   pull_request:
     types: [ closed ]
     paths:
       - '.github/project.yml'
 
 permissions:
   contents: read
-
+  
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 jobs:
   prepare-release:
     name: Prepare Release
-    if: ${{ github.event.pull_request.merged == true}}
+    if: ${{ github.event_name == 'workflow_dispatch' || github.event.pull_request.merged == true}}
     uses: quarkiverse/.github/.github/workflows/prepare-release.yml@main
     secrets: inherit