fix: prevent releases of helm chart with pre-releases of zot (#2755)

Signed-off-by: Andreea-Lupu <[email protected]>

.github/workflows/publish.yaml

@@ -279,7 +279,7 @@ jobs:
           sarif_file: 'trivy-results.sarif'
 
   update-helm-chart:
-    if: github.event_name == 'release' && github.event.action== 'published'
+    if: ${{ github.event_name == 'release' && github.event.action == 'published' && !contains(github.event.release.tag_name, 'rc') }}
     needs: push-multiarch-image
     name: Update Helm Chart
     permissions: