ci: run release job when release message is present

.gitea/workflows/release.yml

@@ -39,6 +39,9 @@ jobs:
   release:
     runs-on: ubuntu-latest
     needs: build
+    if: contains(github.event.head_commit.message, 'Release-As:')
+    env:
+      USERNAME: servostar
     steps:
       - name: Check out repository code
         uses: actions/checkout@v3