Revert "github: don't wait for flatpak build finish, it's broken for us anyway"

This reverts commit eb61bcf76a.

.github/workflows/c-cpp.yml

@@ -92,8 +92,7 @@ jobs:
   release:
     name: "Upload releases"
     runs-on: ubuntu-latest
-    #needs: [build, flatpak]
+    needs: [build, flatpak]
-    needs: build
     if: ${{ github.event_name == 'push' }}
     steps:
     - name: Remove old release