ci: Run the mirror workflow on generic workers

No need to bottleneck on the self hosted worker(s) when this is a light
job.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

.github/workflows/mirror.yml

@@ -12,7 +12,7 @@ concurrency:
 jobs:
   yocto-mirror:
     name: Yocto Git Mirror
-    runs-on: [self-hosted, Linux]
+    runs-on: ubuntu-latest
     steps:
       - uses: agherzan/git-mirror-me-action@11f54c7186724daafbe5303b5075954f1a19a63e
         env: