We no longer need to monky-patch build.has_ext_modules.

All the logic was to replace has_ext_modules with our own version, we our
version is the very same code as the distutils' one.  I'm not even sure
whether it was ever necessary, because distutils does not seem to have changed
since py3.7 at least.

So, I think that this is safe to remove, but I hope it's not a Chesterton's
fence.

hpy/devel/__init__.py

@@ -16,7 +16,6 @@
                     "This most likely means that you are using a version which "
                     "is too old. Try installing setuptools>=60.2")
 from distutils import log
-from distutils.command.build import build
 from distutils.errors import DistutilsError
 import setuptools.command as cmd
 import setuptools.command.build_ext
@@ -67,7 +66,6 @@ def fix_distribution(self, dist):
             Used from both setup.py and hpy/test.
         """
         dist.hpydevel = self
-        base_build = dist.cmdclass.get("build", build)
         build_ext = dist.cmdclass.get("build_ext", cmd.build_ext.build_ext)
 
         # check that the supplied build_ext inherits from setuptools
@@ -89,19 +87,10 @@ def dist_has_ext_modules(self):
                 return True
             return False
 
-        def build_has_ext_modules(self):
-            return self.distribution.has_ext_modules()
-
         # replace build_ext subcommand
         dist.cmdclass['build_ext'] = build_ext_hpy
 
         dist.__class__.has_ext_modules = dist_has_ext_modules
-        base_build.has_ext_modules = build_has_ext_modules
-        # setuptools / distutils store subcommands in .subcommands which
-        # is a list of tuples of (extension_name, extension_needs_to_run_func).
-        # The two lines below replace .subcommand entry for build_ext.
-        idx = [sub[0] for sub in base_build.sub_commands].index("build_ext")
-        base_build.sub_commands[idx] = ("build_ext", build_has_ext_modules)
 
         @monkeypatch(setuptools.command.bdist_egg)
         def write_stub(resource, pyfile):