[lint] remove isort linter, enable isort in ruff

Summary:
For this we need the linter to be aware of the file path, even though we pass it via stdin, so it can detect the proper TOML configuration file to use.

Tested in various ways:

• added unused import, checked that it is automatically removed
• removed required import, checked that it causes a lint error
• messed with the import ordering, checked that they are sorted after arc lint

Depends on D18905

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D18906