fix: Change Inherit from str,enum to StrEnum UP042

Author: johnvox

openapi_python_client/templates/str_enum.py.jinja

@@ -1,6 +1,6 @@
-from enum import Enum
+from enum import StrEnum
 
-class {{ enum.class_info.name }}(str, Enum):
+class {{ enum.class_info.name }}(StrEnum):
     {% for key, value in enum.values|dictsort(true) %}
     {{ key }} = "{{ value }}"
     {% endfor %}