DEV: remove seed isort config
This was causing issues for me locally. Anyone else?

It took a while to run, and didn't seem to give the same
output as others (depends on something peculiar to my environment)
which doesn't seem to be great for a pre-commit hook.

Closes https://github.com/pandas-dev/pandas/issues/28236
OK by me but cc @sbalk and @basnijholt for insight I added it because it solved a particular problem. I didn’t anticipate that it would cause any problems.  I’m also fine with deleting it. 