requests: allow str and bytes for fileobj in files parameter (#7728)

* requests: allow str and bytes for fileobj in files parameter

* requests: Use SupportsRead instead of IO for files

Author: milanboers

stubs/requests/requests/sessions.pyi

@@ -1,4 +1,4 @@
-from _typeshed import Self, SupportsItems
+from _typeshed import Self, SupportsItems, SupportsRead
 from collections.abc import Callable, Iterable, Mapping, MutableMapping
 from typing import IO, Any, Union
 from typing_extensions import TypeAlias
@@ -49,10 +49,10 @@ _Data: TypeAlias = str | bytes | Mapping[str, Any] | Iterable[tuple[str, str | N
 _Auth: TypeAlias = Union[tuple[str, str], _auth.AuthBase, Callable[[PreparedRequest], PreparedRequest]]
 _Cert: TypeAlias = Union[str, tuple[str, str]]
 _Files: TypeAlias = (
-    MutableMapping[str, IO[Any]]
-    | MutableMapping[str, tuple[str | None, IO[Any]]]
-    | MutableMapping[str, tuple[str | None, IO[Any], str]]
-    | MutableMapping[str, tuple[str | None, IO[Any], str, _TextMapping]]
+    MutableMapping[str, SupportsRead[str | bytes] | str | bytes]
+    | MutableMapping[str, tuple[str | None, SupportsRead[str | bytes] | str | bytes]]
+    | MutableMapping[str, tuple[str | None, SupportsRead[str | bytes] | str | bytes, str]]
+    | MutableMapping[str, tuple[str | None, SupportsRead[str | bytes] | str | bytes, str, _TextMapping]]
 )
 _Hook: TypeAlias = Callable[[Response], Any]
 _Hooks: TypeAlias = MutableMapping[str, _Hook | list[_Hook]]