pkg/sql/catalog/lease: make table creation push test resilient

Retry an insert with testutils.SucceedsSoon. This helps to resolve a
testflake where the insert fails because it runs with a timestamp from
before the schema change that created the table. Normally, the
transaction gets pushed, but it can flake in multi-tenant environments.

Release note: none
Closes #157251

Author: spilchen

pkg/sql/catalog/lease/lease_test.go

@@ -1768,7 +1768,7 @@ func TestTableCreationPushesTxnsInRecentPast(t *testing.T) {
 		ServerArgs: base.TestServerArgs{
 			Knobs: base.TestingKnobs{
 				Store: &kvserver.StoreTestingKnobs{
-					MaxOffset: time.Second,
+					MaxOffset: 2 * time.Second,
 				},
 			},
 		},