fix(ci): add Docker login

.forgejo/workflows/functions.yml

@@ -21,6 +21,13 @@ jobs:
           tinygo-version: "0.35.0"
           install-binaryen: "false"
 
+      - name: Login to container registry
+        uses: docker/login-action@v3
+        with:
+          registry: code.icb4dc0.de
+          username: prskr
+          password: ${{ secrets.CONTAINER_REGISTRY_TOKEN }}
+
       - name: Checkout
         uses: actions/checkout@v4