chore(tests): Skip flakey cerboshub audit backend test

The backoff retry is triggered in a separate goroutine, which isn't
guaranteed to complete before the test does. I'm skipping now to unblock
the build and will address in a followup PR

Signed-off-by: Sam Lock <sam@swlock.co.uk>

internal/audit/cerboshub/cerboshub_test.go

@@ -177,6 +177,7 @@ func TestCerbosHubLog(t *testing.T) {
 	})
 
 	t.Run("deletesSyncKeysAfterBackoff", func(t *testing.T) {
+		t.Skip("TODO: We need to block until retry goroutine is complete")
 		t.Cleanup(purgeKeys)
 
 		loadedKeys := loadData(t, db, startDate)