ci: remove runners group

Author: JesusTheHun

.github/workflows/tests.yml

@@ -17,7 +17,6 @@ jobs:
       github.event_name == 'workflow_dispatch'
     timeout-minutes: 30
     runs-on:
-      group: couchbase-runners
       labels: blacksmith-4vcpu-ubuntu-2404
     strategy:
       fail-fast: false