[ci] Build artefact only if commit/push is on a tag. This will automatically create release on tags

Author: epernod

.github/workflows/ci.yml

@@ -114,7 +114,7 @@ jobs:
 
   deploy:
     name: Deploy artifacts
-    if: always() && startsWith(github.ref, 'refs/heads/main') # we are on a branch (not a PR)
+    if: always() && startsWith(github.ref, 'refs/tags/')
     needs: [build-and-test]
     runs-on: ubuntu-latest
     continue-on-error: true