Loosen up some dependencies

Remove code coverage for testing, and allow newer versioneer.

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools>=62.6", "versioneer[toml]==0.29"]
+requires = ["setuptools>=62.6", "versioneer[toml]>=0.29"]
 build-backend = "setuptools.build_meta"
 
 [project]
@@ -105,7 +105,6 @@ addopts = '''
 --ignore=.github
 --strict-markers
 --strict-config
---cov-config=pyproject.toml
 -p no:asyncio
 -p no:legacypath'''
 filterwarnings = [