[3.15] Update mypy to 2.1.0 (GH-149709)

Lib/test/libregrtest/single.py

@@ -145,7 +145,7 @@ def regrtest_runner(result: TestResult, test_func, runtests: RunTests) -> None:
 
 
 # Storage of uncollectable GC objects (gc.garbage)
-GC_GARBAGE = []
+GC_GARBAGE: list[object] = []
 
 
 def _load_run_test(result: TestResult, runtests: RunTests) -> None:

Lib/tomllib/mypy.ini

@@ -12,6 +12,4 @@ pretty = True
 # Enable most stricter settings
 enable_error_code = ignore-without-code
 strict = True
-strict_bytes = True
-local_partial_types = True
 warn_unreachable = True

Tools/build/check_extension_modules.py

@@ -463,7 +463,7 @@ def get_location(self, modinfo: ModuleInfo) -> pathlib.Path | None:
     def _check_file(self, modinfo: ModuleInfo, spec: ModuleSpec) -> None:
         """Check that the module file is present and not empty"""
         if spec.loader is BuiltinImporter:  # type: ignore[comparison-overlap]
-            return
+            return  # type: ignore[unreachable]
         try:
             assert spec.origin is not None
             st = os.stat(spec.origin)

Tools/build/mypy.ini

@@ -24,8 +24,6 @@ python_version = 3.10
 
 # ...And be strict:
 strict = True
-strict_bytes = True
-local_partial_types = True
 extra_checks = True
 enable_error_code = ignore-without-code,redundant-expr,truthy-bool,possibly-undefined
 warn_unreachable = True

Tools/requirements-dev.txt

@@ -1,7 +1,7 @@
 # Requirements file for external linters and checks we run on
 # Tools/clinic, Tools/cases_generator/, and Tools/peg_generator/ in CI
-mypy==1.19.1
+mypy==2.1.0
 
 # needed for peg_generator:
-types-psutil==7.2.2.20260130
-types-setuptools==82.0.0.20260210
+types-psutil==7.2.2.20260508
+types-setuptools==82.0.0.20260508