python: adjust basic typing information (#17511)

* python: adjust basic typing information

This is an initial pass to fix and adjust the typing information for the
generated client. This is enough to have mypy runnning without complains
on all the (modern) generated clients (Pydantic v1 code is not checked
for instance)

mypy is also now run directly in the CI, so further changes will also be
checked and thus, will need to be compliant with good typing
information.

Note that this doesn't *fully* type all the code: mypy is not run in
"strict" mode and there are still many functions/methods/attributes
which are still not fully typed, but it's a first good step in that
direction.

* ApiResponse's raw_data can't be None

* Fix indentation

* Revert test changes

* run mypy on tests/ directory

* don't forcefully convert the client response headers to dict

* override petstore ApiResponse model

* adjust type of 'any/one_of_schemas' fields

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/api/auth_api.py

@@ -15,11 +15,7 @@
 import warnings
 from pydantic import validate_call, Field, StrictFloat, StrictStr, StrictInt
 from typing import Any, Dict, List, Optional, Tuple, Union
-
-try:
-    from typing import Annotated
-except ImportError:
-    from typing_extensions import Annotated
+from typing_extensions import Annotated
 
 
 from openapi_client.api_client import ApiClient

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/api/body_api.py

@@ -15,11 +15,7 @@
 import warnings
 from pydantic import validate_call, Field, StrictFloat, StrictStr, StrictInt
 from typing import Any, Dict, List, Optional, Tuple, Union
-
-try:
-    from typing import Annotated
-except ImportError:
-    from typing_extensions import Annotated
+from typing_extensions import Annotated
 
 from pydantic import Field, StrictBytes, StrictStr
 from typing import Any, Dict, List, Optional, Union

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/api/form_api.py

@@ -15,11 +15,7 @@
 import warnings
 from pydantic import validate_call, Field, StrictFloat, StrictStr, StrictInt
 from typing import Any, Dict, List, Optional, Tuple, Union
-
-try:
-    from typing import Annotated
-except ImportError:
-    from typing_extensions import Annotated
+from typing_extensions import Annotated
 
 from pydantic import StrictBool, StrictInt, StrictStr
 from typing import Optional

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/api/header_api.py

@@ -15,11 +15,7 @@
 import warnings
 from pydantic import validate_call, Field, StrictFloat, StrictStr, StrictInt
 from typing import Any, Dict, List, Optional, Tuple, Union
-
-try:
-    from typing import Annotated
-except ImportError:
-    from typing_extensions import Annotated
+from typing_extensions import Annotated
 
 from pydantic import StrictBool, StrictInt, StrictStr, field_validator
 from typing import Optional

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/api/path_api.py

@@ -15,11 +15,7 @@
 import warnings
 from pydantic import validate_call, Field, StrictFloat, StrictStr, StrictInt
 from typing import Any, Dict, List, Optional, Tuple, Union
-
-try:
-    from typing import Annotated
-except ImportError:
-    from typing_extensions import Annotated
+from typing_extensions import Annotated
 
 from pydantic import StrictInt, StrictStr, field_validator
 from openapi_client.models.string_enum_ref import StringEnumRef

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/api/query_api.py

@@ -15,11 +15,7 @@
 import warnings
 from pydantic import validate_call, Field, StrictFloat, StrictStr, StrictInt
 from typing import Any, Dict, List, Optional, Tuple, Union
-
-try:
-    from typing import Annotated
-except ImportError:
-    from typing_extensions import Annotated
+from typing_extensions import Annotated
 
 from datetime import date, datetime
 from pydantic import StrictBool, StrictInt, StrictStr, field_validator