Fix schema generation for newer pydantic version

Author: lord-haffi

generate_or_validate_json_schemas.py

@@ -117,10 +117,21 @@ def get_schema_json_dict(cls: Any) -> dict[str, Any]:
         reference_match = reference_pattern.fullmatch(schema_json_dict["allOf"][0]["$ref"])
         assert (
             reference_match is not None
-        ), "Internal Error: Reference string has unexpected format: {schema_json_dict['allOf'][0]['$ref']}"
+        ), f"Internal Error: Reference string has unexpected format: {schema_json_dict['allOf'][0]['$ref']}"
         schema_json_dict_to_merge = schema_json_dict["$defs"][reference_match.group("cls_name")]
         del schema_json_dict["allOf"]
         schema_json_dict.update(schema_json_dict_to_merge)
+    if {"$ref", "$defs"} == set(schema_json_dict.keys()):
+        # The newer version of pydantic sometimes generates a schema with only a $ref and a $defs key where the $ref
+        # field points to the actual schema definition in the $defs field.
+        reference_pattern = re.compile(r"^#/\$defs/(?P<cls_name>\w+)$")
+        reference_match = reference_pattern.fullmatch(schema_json_dict["$ref"])
+        assert (
+            reference_match is not None
+        ), f"Internal Error: Reference string has unexpected format: {schema_json_dict['$ref']}"
+        schema_json_dict_to_merge = schema_json_dict["$defs"][reference_match.group("cls_name")]
+        del schema_json_dict["$ref"]
+        schema_json_dict.update(schema_json_dict_to_merge)
     if "$defs" in schema_json_dict:
         del schema_json_dict["$defs"]
     return schema_json_dict