increase size in test_multinomial_counterexample (tinygrad#9540)

should be less flaky

Author: chenyuxyz

test/test_randomness.py

@@ -319,10 +319,10 @@ def sample_one(): return Tensor(w).multinomial(1, replacement=False).realize()
       self.assertTrue(equal_distribution(lambda *_: Tensor(tiny_samples), lambda _: torch.tensor(torch_samples)))
 
   def test_multinomial_counterexample(self):
-    tiny_res = Tensor([0.3, 0.6, 0.1]).multinomial(2000, replacement=True)
-    torch_res = torch.tensor([0.3, 0.6, 0.1]).multinomial(2000, replacement=True)
+    tiny_res = Tensor([0.3, 0.6, 0.1]).multinomial(4000, replacement=True)
+    torch_res = torch.tensor([0.3, 0.6, 0.1]).multinomial(4000, replacement=True)
     self.assertTrue(equal_distribution(lambda *_: tiny_res, lambda _: torch_res))
-    torch_res = torch.tensor([0.2, 0.7, 0.1]).multinomial(2000, replacement=True)
+    torch_res = torch.tensor([0.2, 0.7, 0.1]).multinomial(4000, replacement=True)
     self.assertFalse(equal_distribution(lambda *_: tiny_res, lambda _: torch_res))
 
   def test_conv2d_init(self):