backup: skip/remove some tests

These were flaking CI.
- remove TestDataDriven/show_backups which was testing a 22.2 fixture
- skip TestShowbackupPathIsCollectionRoot
- skip TestRegistryLifecycle

Informs #152542

Release note: none

Author: msbutler

pkg/backup/show_test.go

@@ -705,6 +705,7 @@ func TestShowBackupWithDebugIDs(t *testing.T) {
 func TestShowBackupPathIsCollectionRoot(t *testing.T) {
 	defer leaktest.AfterTest(t)()
 	defer log.Scope(t).Close(t)
+	skip.WithIssue(t, 152935)
 
 	const numAccounts = 11
 

pkg/backup/testdata/backup-restore/show_backup

@@ -392,6 +392,7 @@ func (rts *registryTestSuite) idb() isql.DB {
 func TestRegistryLifecycle(t *testing.T) {
 	defer leaktest.AfterTest(t)()
 	defer log.Scope(t).Close(t)
+	skip.WithIssue(t, 152542)
 
 	t.Run("normal success", func(t *testing.T) {
 		rts := registryTestSuite{}