.github: make release message job depend on builds

Make sure the release message won't be created when build jobs on the
release tag didn't succeed.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>

.github/workflows/build-xserver.yml

@@ -192,6 +192,10 @@ jobs:
         name: Release pushed tag
         runs-on: ubuntu-latest
         if: ${{ startsWith(github.ref, 'refs/tags/xlibre-xserver-') }}
+        needs:
+            - xserver-build-ubuntu
+            - drivers-build-ubuntu
+            - xserver-build-macos
         steps:
             - name: Checkout
               uses: actions/checkout@v4