Remove unnecessary build-system entries

build-requirements.txt

@@ -1,4 +1,3 @@
-# NOTE: this needs to be kept in sync with the "requires" list in pyproject.toml
 -r mypy-requirements.txt
 types-psutil
 types-setuptools

mypy-requirements.txt

@@ -1,4 +1,3 @@
-# NOTE: this needs to be kept in sync with the "requires" list in pyproject.toml
 typing_extensions>=3.10
 mypy_extensions>=0.4.3
 typed_ast>=1.4.0,<2; python_version<'3.8'

pyproject.toml

@@ -1,19 +1,7 @@
 [build-system]
 requires = [
-    # NOTE: this needs to be kept in sync with mypy-requirements.txt
-    # and build-requirements.txt, because those are both needed for
-    # self-typechecking :/
     "setuptools >= 40.6.2",
     "wheel >= 0.30.0",
-    # the following is from mypy-requirements.txt
-    "typing_extensions>=3.10",
-    "mypy_extensions>=0.4.3",
-    "typed_ast>=1.4.0,<2; python_version<'3.8'",
-    "tomli>=1.1.0; python_version<'3.11'",
-    # the following is from build-requirements.txt
-    "types-psutil",
-    "types-setuptools",
-    "types-typed-ast>=1.5.8,<1.6.0",
 ]
 build-backend = "setuptools.build_meta"