Fix setuptools 76.1 issue (and bump to >=77.0.3)

pyproject.toml

@@ -1,7 +1,8 @@
 [build-system]
-# As of setuptools==74, we no longer need to
-# be concerned about distutils calling win32api
-# setuptools==76.1 breaks building of .mc files
-# win32/src/PythonService.cpp(49): fatal error C1083: Cannot open include file: 'PythonServiceMessages.h': No such file or directory
-requires = ["setuptools>=74,<76.1"]
+# setuptools==77.0.3 made PEP-639 license deprecations introduced by 77.0.0 into warnings rather than errors
+# setuptools==75.4 dropped support for Python 3.8
+requires = [
+  "setuptools >=77.0.3; python_version >='3.9'",
+  "setuptools <76.1; python_version <'3.9'",
+]
 build-backend = "setuptools.build_meta"

setup.py

@@ -36,8 +36,8 @@
 from collections.abc import MutableSequence
 from pathlib import Path
 from setuptools import Extension, setup
+from setuptools._distutils import ccompiler
 from setuptools.command.build import build
-from setuptools.command.build_ext import build_ext
 from setuptools.modified import newer_group
 from tempfile import gettempdir
 from typing import TYPE_CHECKING, Iterable
@@ -53,6 +53,21 @@
     from distutils._msvccompiler import MSVCCompiler
     from distutils.command.install_data import install_data
 
+
+def my_new_compiler(**kw):
+    if "compiler" in kw and kw["compiler"] in (None, "msvc"):
+        return my_compiler()
+    return orig_new_compiler(**kw)
+
+
+# No way to cleanly wedge our compiler sub-class in.
+orig_new_compiler = ccompiler.new_compiler
+ccompiler.new_compiler = my_new_compiler  # type: ignore[assignment] # Assuming the caller will always use only kwargs
+
+
+# This import has to be delayed to AFTER the compiler hack
+from setuptools.command.build_ext import build_ext  # noqa: E402
+
 build_id_patch = build_id
 if not "." in build_id_patch:
     build_id_patch += ".0"
@@ -856,17 +871,6 @@ def swig_sources(self, sources, ext=None):
         return new_sources
 
 
-def my_new_compiler(**kw):
-    if "compiler" in kw and kw["compiler"] in (None, "msvc"):
-        return my_compiler()
-    return orig_new_compiler(**kw)
-
-
-# No way to cleanly wedge our compiler sub-class in.
-orig_new_compiler = ccompiler.new_compiler
-ccompiler.new_compiler = my_new_compiler  # type: ignore[assignment] # Assuming the caller will always use only kwargs
-
-
 class my_compiler(MSVCCompiler):
     def link(
         self,