refactor(general): drop pydantic v1 (#4305)

Author: leandrodamascena

aws_lambda_powertools/event_handler/api_gateway.py

@@ -1587,22 +1587,16 @@ def _get_openapi_security(
         return security
 
     @staticmethod
-    def _determine_openapi_version(openapi_version):
-        from aws_lambda_powertools.event_handler.openapi.pydantic_loader import PYDANTIC_V2
+    def _determine_openapi_version(openapi_version: str):
 
         # Pydantic V2 has no support for OpenAPI schema 3.0
-        if PYDANTIC_V2 and not openapi_version.startswith("3.1"):
+        if not openapi_version.startswith("3.1"):
             warnings.warn(
                 "You are using Pydantic v2, which is incompatible with OpenAPI schema 3.0. Forcing OpenAPI 3.1",
                 stacklevel=2,
             )
             openapi_version = "3.1.0"
-        elif not PYDANTIC_V2 and not openapi_version.startswith("3.0"):
-            warnings.warn(
-                "You are using Pydantic v1, which is incompatible with OpenAPI schema 3.1. Forcing OpenAPI 3.0",
-                stacklevel=2,
-            )
-            openapi_version = "3.0.3"
+
         return openapi_version
 
     def get_openapi_json_schema(