fix(ci): use act-latest container for Docker and Node.js support

Replace manual Node.js install with catthehacker/ubuntu:act-latest
container which includes Node.js, Docker, and all build dependencies
needed for Gitea Actions.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitea/workflows/build-package.yaml

@@ -9,15 +9,10 @@ on:
 jobs:
   build-and-push:
     runs-on: ubuntu-latest
+    container: docker.io/catthehacker/ubuntu:act-latest
     timeout-minutes: 15
 
     steps:
-      - name: Install Node.js 20 (required for actions)
-        run: |
-          apt-get update && apt-get install -y curl git
-          curl -fsSL https://deb.nodesource.com/setup_20.x | bash -
-          apt-get install -y nodejs
-
       - name: Checkout repository
         uses: actions/checkout@v4