Add required configuration for pytest-codecov 7

In 7.0.0 pytest-cov removed its custom handling of subprocess handling.
Instead we now use coverage's system.

Author: AlexanderWells-diamond

setup.cfg

@@ -82,3 +82,4 @@ asyncio_mode = auto
 [coverage:run]
 # This is covered in the versiongit test suite so exclude it here
 omit = */_version_git.py
+patch = subprocess