[release-19.0] Remove concurrency group for check labels workflow (#15197) (#15209)

Signed-off-by: Florent Poinsard <florent.poinsard@outlook.fr>
Co-authored-by: vitess-bot[bot] <108069721+vitess-bot[bot]@users.noreply.github.com>

Author: vitess-bot[bot]

.github/workflows/check_label.yml

@@ -3,10 +3,6 @@ on:
   pull_request:
     types: [opened, labeled, unlabeled, synchronize]
 
-concurrency:
-  group: format('{0}-{1}', ${{ github.ref }}, 'Check Pull Request labels')
-  cancel-in-progress: true
-
 permissions: read-all
 
 jobs: