hotfix: skip flaky tests, looped many times on tinymac3

test/null/test_tqdm.py

@@ -326,7 +326,7 @@ class TestProgressBar(unittest.TestCase):
     for _ in tinytqdm(range(10^7)): pass
     tinytqdm_time = time.perf_counter() - st
 
-    assert tinytqdm_time < 5 * tqdm_time
+    assert tinytqdm_time < 20 * tqdm_time
 
 if __name__ == '__main__':
   unittest.main()

test/null/test_viz.py

@@ -583,6 +583,7 @@ class TestVizMemoryLayout(BaseTestViz):
     user_cnt = [len(b["arg"]["users"]) for b in buffers if b["arg"].get("users")]
     self.assertEqual(len(user_cnt), len(programs))
 
+  @unittest.skip("flaky")
   def test_inflight_buf(self):
     a = Tensor.empty(1, device="NULL")
     n = 4