fix: CI - remove github actions, use raw docker

.gitea/workflows/docker-build.yml

@@ -11,15 +11,12 @@ jobs:
   build-and-push:
     runs-on: linux
     steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-
-      - name: Login to Gitea Container Registry
-        uses: docker/login-action@v3
-        with:
-          registry: git.kgessner.de
-          username: ${{ secrets.REGISTRY_USER }}
-          password: ${{ secrets.REGISTRY_TOKEN }}
+      - name: Login to Container Registry
+        run: |
+          echo "$REGISTRY_TOKEN" | docker login git.kgessner.de -u "$REGISTRY_USER" --password-stdin
+        env:
+          REGISTRY_USER: ${{ secrets.REGISTRY_USER }}
+          REGISTRY_TOKEN: ${{ secrets.REGISTRY_TOKEN }}
 
       - name: Build Docker Image
         run: |