📦 Drop unnecessary wheel PEP 517 build dependency (#80096)

Code snippets advertising the `wheel` dependency in the
`pyproject.toml`'s `[build-system].requires` setting were a historical
mistake. This has been corrected in
https://github.com/pypa/setuptools/commit/f7d30a95 but many pyprojects
still have `wheel` in their configs.

It is not needed for building sdists and the corresponding setuptools'
PEP 517 hook that provides requirements for building wheels already
esposes this dependency automatically.

pyproject.toml

@@ -1,4 +1,4 @@
 [build-system]
-requires = ["setuptools >= 39.2.0", "wheel"]
+requires = ["setuptools >= 39.2.0"]
 backend-path = ["packaging"]  # requires 'Pip>=20' or 'pep517>=0.6.0'
 build-backend = "pep517_backend.hooks"  # wraps `setuptools.build_meta`