remove pointless typing-ext dep
--
diff --git a/setup.cfg b/setup.cfg
index 12903ea..c6e762e 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -30,7 +30,6 @@ zip_safe = True
 install_requires =
     setuptools>=62.4
     semantic_version>=2.8.2,<3
-    typing_extensions>=3.7.4.3
 setup_requires = setuptools>=62.4
 python_requires = >=3.7
 
diff --git a/setuptools_rust/build.py b/setuptools_rust/build.py
index 9a039ca..8e3e0dc 100644
--- a/setuptools_rust/build.py
+++ b/setuptools_rust/build.py
@@ -24,7 +24,7 @@ from semantic_version import Version
 from setuptools.command.build import build as CommandBuild  # type: ignore[import]
 from setuptools.command.build_ext import build_ext as CommandBuildExt
 from setuptools.command.build_ext import get_abi3_suffix
-from typing_extensions import Literal
+from typing import Literal
 
 from ._utils import format_called_process_error
 from .command import RustCommand
diff --git a/setuptools_rust/extension.py b/setuptools_rust/extension.py
index f7a09d1..537a8db 100644
--- a/setuptools_rust/extension.py
+++ b/setuptools_rust/extension.py
@@ -9,7 +9,7 @@ from functools import lru_cache
 from typing import Any, Dict, List, NewType, Optional, Sequence, Union, cast
 
 from semantic_version import SimpleSpec
-from typing_extensions import Literal
+from typing import Literal
 
 from ._utils import format_called_process_error
 
diff --git a/setuptools_rust/setuptools_ext.py b/setuptools_rust/setuptools_ext.py
index ab51d16..550cfb5 100644
--- a/setuptools_rust/setuptools_ext.py
+++ b/setuptools_rust/setuptools_ext.py
@@ -11,7 +11,7 @@ from setuptools.command.install_lib import install_lib
 from setuptools.command.install_scripts import install_scripts
 from setuptools.command.sdist import sdist
 from setuptools.dist import Distribution
-from typing_extensions import Literal
+from typing import Literal
 
 from .extension import RustBin, RustExtension