Drop wheel from build requirements; no longer needed as of setuptools 70.1 (#2439)

* drop wheel; bump setuptools to >=70.1

setuptools 70.1.0 brought in the `bdist_wheel` command from `wheel`: https://setuptools.pypa.io/en/stable/history.html#v70-1-0

* whatsnew

* Update v0.12.1.rst

Author: kandersolar

docs/sphinx/source/whatsnew/v0.12.1.rst

@@ -24,6 +24,10 @@ Documentation
 * Documented how `np.nan` values are handled by :py:func:`~pvlib.spectrum.average_photon_energy`
   (:issue:`2423`, :pull:`2426`)
 
+Requirements
+~~~~~~~~~~~~
+* ``wheel`` is no longer a build dependency. (:pull:`2439`)
+
 Testing
 ~~~~~~~
 

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools>=61", "wheel", "setuptools_scm>=6.2"]
+requires = ["setuptools>=70.1", "setuptools_scm>=6.2"]
 build-backend = "setuptools.build_meta"