Let's pin in pyproject.toml too

Mostly since it's non-build-backend specific configuration and more
widely standardized file. Not sure what benefits pinning in setup.cfg
gives us on top of pyproject.toml but I'd rather not find out during
the release that is supposed to happen today 😉

CHANGES.md

@@ -13,7 +13,7 @@
   trailing comma (#2384)
 - Parsing support has been added for unparenthesized walruses in set literals, set
   comprehensions, and indices (#2447).
-- Pin `setuptools-scm` dependency version (#2449)
+- Pin `setuptools-scm` build-time dependency version (#2450)
 
 ### _Blackd_
 

pyproject.toml

@@ -23,7 +23,10 @@ extend-exclude = '''
 # NOTE: You don't need this in your own Black configuration.
 
 [build-system]
-requires = ["setuptools>=41.0", "setuptools-scm", "wheel"]
+# We're pinning setuptools-scm to bugfix versions only because for build-time
+# deps having them work on install by default is really important. Especially
+# since it's hard for users to work-around the specified build requirements.
+requires = ["setuptools>=41.0", "setuptools_scm~=6.0.1", "wheel"]
 build-backend = "setuptools.build_meta"
 
 [tool.pytest.ini_options]

setup.cfg

@@ -1,3 +1,3 @@
 [options]
-setup_requires = 
+setup_requires =
   setuptools_scm~=6.0.1