fix(ci): use ubuntu-latest runner for release workflow

Match CI workflow pattern — runs-on: ubuntu-latest with DinD runner.

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

.forgejo/workflows/release.yml

@@ -7,10 +7,9 @@ on:
 
 jobs:
   publish:
-    runs-on: docker
+    runs-on: ubuntu-latest
     steps:
-      - name: Checkout code
-        uses: actions/checkout@v4
+      - uses: actions/checkout@v4
 
       - name: Extract version from tag
         id: version