fix: remove deprecated gpt-4-32k model from test

The model that this test uses is no longer available online. [1] [2]

Per the upstream commit, the only known suitable replacement is
gpt-4-0613, which the test already uses.

Hence, remove gpt-4-32k from the test without any replacement.

[1]: https://github.com/BerriAI/litellm/pull/20795

[2]: 15075ef9ec

tests/basic/test_models.py

@@ -43,9 +43,6 @@ class TestModels(unittest.TestCase):
         model = Model("gpt-4")
         self.assertEqual(model.info["max_input_tokens"], 8 * 1024)
 
-        model = Model("gpt-4-32k")
-        self.assertEqual(model.info["max_input_tokens"], 32 * 1024)
-
         model = Model("gpt-4-0613")
         self.assertEqual(model.info["max_input_tokens"], 8 * 1024)