Add container config to build action.

.gitea/workflows/build.yml

@@ -6,6 +6,10 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    container:
+      image: docker.gitea.com/runner-images:ubuntu-latest
+      volumes:
+        - /home/www/ooru.space:/site-output
     steps:
       - uses: actions/checkout@v4