fix(ci): use rpm runner for package and publish jobs

The cuda-13.0 container used for build jobs does not have RPM build
tools. Switch package and publish jobs to the rpm runner which includes
rpmdev-setuptree, rpmbuild, and sequoia-sq.

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

.gitea/workflows/build-prerelease.yml

@@ -100,7 +100,7 @@ jobs:
 
   package:
     needs: build
-    runs-on: fedora-43
+    runs-on: rpm
     strategy:
       fail-fast: false
       matrix:
@@ -143,7 +143,7 @@ jobs:
 
   publish:
     needs: package
-    runs-on: fedora-43
+    runs-on: rpm
     concurrency:
       group: rpm-publish
       cancel-in-progress: false