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/build-release.yml

@@ -73,7 +73,7 @@ jobs:
 
   package:
     needs: build
-    runs-on: fedora
+    runs-on: fedora-43
     strategy:
       fail-fast: false
       matrix:
@@ -114,7 +114,7 @@ jobs:
 
   publish:
     needs: package
-    runs-on: fedora
+    runs-on: fedora-43
     strategy:
       fail-fast: false
       matrix: