Investigate potential bug with graceful shutdown

[pleshakov]

During shutdown in a longevity test, the following error was shown

INFO 2024-03-20T14:13:00.372305088Z [resource.labels.containerName: nginx-gateway] {"level":"info", "msg":"Wait completed, proceeding to shutdown the manager", "ts":"2024-03-20T14:13:00Z"}
ERROR 2024-03-20T14:13:00.374159128Z [resource.labels.containerName: nginx-gateway] {"error":"leader election lost", "level":"error", "msg":"error received after stop sequence was engaged", "stacktrace":"sigs.k8s.io/controller-runtime/pkg/manager.(*controllerManager).engageStopProcedure.func1 sigs.k8s.io/controller-runtime@v0.17.2/pkg/manager/internal.go:490", "ts":"2024-03-20T14:13:00Z"}

not clear if this can cause any issue and needs to be fixed.

[github-actions]

This issue is stale because it has been open 14 days with no activity. Remove stale label or comment or this will be closed in 14 days.

[mpstefan]

If this occurs only during shutdown on the longevity test, I'm not sure this is worth investigating until we see this more than once or we have a better idea of impact, as this investigation could take a while.