Add the GeLU activation from pytorch with the tanh approximation (#21345)

* gelu_python_tanh

* rename

* Version check, add test

* Pr comment

tests/utils/test_activations.py

@@ -51,6 +51,7 @@ class TestActivations(unittest.TestCase):
         get_activation("gelu_fast")
         get_activation("gelu_new")
         get_activation("gelu_python")
+        get_activation("gelu_pytorch_tanh")
         get_activation("linear")
         get_activation("mish")
         get_activation("quick_gelu")