Revert "Update pydantic hack"

This reverts commit ef055f6.

Author: dandavison

temporalio/converter.py

@@ -1523,12 +1523,11 @@ def value_to_type(
         # TODO(cretz): Want way to convert snake case to camel case?
         return hint(**field_values)
 
-    # Use validate() method if present (suggests it is a Pydantic model)
-    pydantic_validate_attr = inspect.getattr_static(
-        hint, "validate", None
-    ) or inspect.getattr_static(hint, "parse_obj", None)
-    if isinstance(pydantic_validate_attr, classmethod) or isinstance(
-        pydantic_validate_attr, staticmethod
+    # If there is a @staticmethod or @classmethod parse_obj, we will use it.
+    # This covers Pydantic models.
+    parse_obj_attr = inspect.getattr_static(hint, "parse_obj", None)
+    if isinstance(parse_obj_attr, classmethod) or isinstance(
+        parse_obj_attr, staticmethod
     ):
         if not isinstance(value, dict):
             raise TypeError(