TST/CLN: Reuse top level fixtures instead of parametrizations
Going to merge this in. Can follow up if needed It seems that the changes in ExtensionArray tests done here break testing of EAs in downstream packages. Those do not have access to fixtures defined in pandas conftest.py and since this PR relies on them, it breaks. See this outcome of GeoPandas CI using the latest nightly https://github.com/bnaul/geopandas/actions/runs/7402184055/job/20139507247.  Sorry for the breakage. I opened up a PR in geopandas to fix this https://github.com/geopandas/geopandas/pull/3121

Our distribution of ExtensionArray tests is still a big fragile; I see you had to define some additional fixtures previously that were in `pandas/conftest.py`