fix(ci): remove job-level concurrency group from publish

Gitea may not support matrix expressions in job-level concurrency
groups. The workflow-level concurrency group already prevents
parallel runs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/build-release.yml

@@ -114,9 +114,6 @@ jobs:
   publish:
     needs: package
     runs-on: fedora
-    concurrency:
-      group: rpm-publish-fc${{ matrix.fedora_version }}
-      cancel-in-progress: false
     strategy:
       fail-fast: false
       matrix: