chore: update action ref to public/actions

(cherry picked from commit f8d4c6a47d)

.gitea/workflows/build.yml

@@ -16,10 +16,9 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: https://git.librete.ch/libretech/actions/.gitea/actions/docker-build@main
+      - uses: https://git.librete.ch/public/actions/.gitea/actions/docker-build@main
         with:
           registry: ${{ secrets.REGISTRY }}
           registry_user: ${{ secrets.REGISTRY_USER }}
           registry_pass: ${{ secrets.REGISTRY_PASS }}
           publish: ${{ github.event_name == 'push' && vars.PUBLISH_ENABLED == 'true' }}
-