Remove redundant wheel dep from pyproject.toml (#110)

Remove the redundant `wheel` dependency, as it is added by the backend
automatically.  Listing it explicitly in the documentation was
a historical mistake and has been fixed since, see:
pypa/setuptools@f7d30a9

Co-authored-by: Dustin Ingram <[email protected]>

Author: mgorny

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools", "wheel", "calver"]
+requires = ["setuptools", "calver"]
 build-backend = "setuptools.build_meta"
 
 [mypy]