kvfollowerreadsccl: skip tests that break when run as secondary tenants

We probabilistically run SQL using secondary tenant connections
in tests. This breaks TestBoundedStalenessDataDriven and
TestFollowerReadsWithStaleDescriptor.

Both these tests configure SQL testing knobs to trace statements and
then make assertions on the collected traces. As these testing knobs
aren't shared by the secondary tenant `TestServer` starts the test
simply doesn't work. For now, we simply eschew running these tests with
secondary tenants.

Release note: None

pkg/ccl/kvccl/kvfollowerreadsccl/boundedstaleness_test.go

@@ -273,6 +273,7 @@ func TestBoundedStalenessDataDriven(t *testing.T) {
 	for i := 0; i < numNodes; i++ {
 		i := i
 		clusterArgs.ServerArgsPerNode[i] = base.TestServerArgs{
+			DisableDefaultTestTenant: true,
 			Knobs: base.TestingKnobs{
 				SQLExecutor: &sql.ExecutorTestingKnobs{
 					WithStatementTrace: func(trace tracingpb.Recording, stmt string) {

pkg/ccl/kvccl/kvfollowerreadsccl/followerreads_test.go

@@ -568,13 +568,17 @@ func TestFollowerReadsWithStaleDescriptor(t *testing.T) {
 	tc := testcluster.StartTestCluster(t, 4,
 		base.TestClusterArgs{
 			ReplicationMode: base.ReplicationManual,
-			ServerArgs:      base.TestServerArgs{UseDatabase: "t"},
+			ServerArgs: base.TestServerArgs{
+				DisableDefaultTestTenant: true,
+				UseDatabase:              "t",
+			},
 			// n4 pretends to have low latency to n2 and n3, so that it tries to use
 			// them for follower reads.
 			// Also, we're going to collect a trace of the test's final query.
 			ServerArgsPerNode: map[int]base.TestServerArgs{
 				3: {
-					UseDatabase: "t",
+					DisableDefaultTestTenant: true,
+					UseDatabase:              "t",
 					Knobs: base.TestingKnobs{
 						KVClient: &kvcoord.ClientTestingKnobs{
 							// Inhibit the checking of connection health done by the