fix(ci): use fedora-43 runner label for all non-build jobs

Ensures package, publish, and poll-upstream jobs are picked up by
Fedora 43 runners specifically.

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

.gitea/workflows/poll-upstream.yml

@@ -11,7 +11,7 @@ concurrency:
 
 jobs:
   check:
-    runs-on: fedora
+    runs-on: fedora-43
     steps:
       - name: Get upstream latest tag
         id: upstream