feat(ci): update Gitea workflow to include registry login and cache handling adjustments

.gitea/workflows/test.yml

@@ -6,6 +6,9 @@ on:
   pull_request:
     branches: [main]
 
+env:
+  REGISTRY: git.arthurerlich.de
+
 jobs:
   build-dev:
     runs-on: ubuntu-latest
@@ -16,6 +19,16 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
+      # type=gha depends on act_runner's internal cache proxy, which is unreachable
+      # from job containers on this runner (dial tcp ... i/o timeout). Use the
+      # registry cache backend instead, same as docker-publish.yml.
+      - name: Log in to Gitea registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ gitea.actor }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
       - name: Build dev image (PHP 8.4 + composer deps)
         uses: docker/build-push-action@v5
         with:
@@ -24,8 +37,8 @@ jobs:
           target: dev
           outputs: type=docker,dest=/tmp/graph-dev.tar
           tags: graph-dev:ci
-          cache-from: type=gha
-          cache-to: type=gha,mode=max
+          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ gitea.repository }}:buildcache-dev
+          cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ gitea.repository }}:buildcache-dev,mode=max
 
       - name: Upload dev image
         uses: actions/upload-artifact@v4