Merge pull request 'Update docker/login-action action to v4' (#4) from renovate/docker-login-action-4.x into main

Reviewed-on: #4

.gitea/workflows/build_push.yaml

@@ -16,7 +16,7 @@ jobs:
         uses: actions/checkout@v7
 
       - name: Login to Docker Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: gitea.psi.ch
           username: ${{ github.repository_owner }}