ccl,kv: skip a few flakey tests/sub-tests

Relevant test failure issues: cockroachdb#66991, cockroachdb#67034, cockroachdb#66942, cockroachdb#66480, cockroachdb#64313.

Release note: None

pkg/ccl/changefeedccl/changefeed_test.go

@@ -2332,7 +2332,10 @@ func TestChangefeedSchemaTTL(t *testing.T) {
 	t.Run("enterprise", enterpriseTest(testFn))
 	t.Run("cloudstorage", cloudStorageTest(testFn))
 	t.Run("kafka", kafkaTest(testFn))
-	t.Run(`webhook`, webhookTest(testFn))
+	t.Run(`webhook`, func(t *testing.T) {
+		skip.WithIssue(t, 66991, "flaky test")
+		webhookTest(testFn)(t)
+	})
 }
 
 func TestChangefeedErrors(t *testing.T) {
@@ -3221,7 +3224,10 @@ func TestManyChangefeedsOneTable(t *testing.T) {
 	t.Run(`enterprise`, enterpriseTest(testFn))
 	t.Run(`cloudstorage`, cloudStorageTest(testFn))
 	t.Run(`kafka`, kafkaTest(testFn))
-	t.Run(`webhook`, webhookTest(testFn))
+	t.Run(`webhook`, func(t *testing.T) {
+		skip.WithIssue(t, 67034, "flakey test")
+		webhookTest(testFn)(t)
+	})
 }
 
 func TestUnspecifiedPrimaryKey(t *testing.T) {

pkg/kv/kvserver/client_merge_test.go

@@ -4378,6 +4378,7 @@ func TestMergeQueue(t *testing.T) {
 	})
 
 	t.Run("sticky-bit-expiration", func(t *testing.T) {
+		skip.WithIssue(t, 66942, "flakey test")
 		manualSplitTTL := time.Millisecond * 200
 		reset(t)
 		store.MustForceMergeScanAndProcess()

pkg/kv/kvserver/client_split_test.go

@@ -2010,6 +2010,7 @@ func TestStoreSplitGCThreshold(t *testing.T) {
 // and the uninitialized replica reacting to messages.
 func TestStoreRangeSplitRaceUninitializedRHS(t *testing.T) {
 	defer leaktest.AfterTest(t)()
+	skip.WithIssue(t, 66480, "flaky test")
 	defer log.Scope(t).Close(t)
 
 	currentTrigger := make(chan *roachpb.SplitTrigger, 1)

pkg/kv/kvserver/replica_test.go

@@ -5606,6 +5606,7 @@ func TestPushTxnAlreadyCommittedOrAborted(t *testing.T) {
 // test cases, the priorities are set such that the push will succeed.
 func TestPushTxnUpgradeExistingTxn(t *testing.T) {
 	defer leaktest.AfterTest(t)()
+	skip.WithIssue(t, 64313, "flaky test")
 	defer log.Scope(t).Close(t)
 	tc := testContext{}
 	stopper := stop.NewStopper()