Fix tests under uv with complex git config

Add pytest-asyncio to the dev group so pytest can run async TUI
tests.

Pin git-filter-repo to unreleased commit 4697eeb for the multiline
git config parser fix requested in
https://github.com/newren/git-filter-repo/issues/638.

That parser fix is the only functional change since v2.47.0:
https://github.com/newren/git-filter-repo/compare/v2.47.0...4697eeb37b7c3c30b0492e344f6b89f7139cef26

Inject commit.gpgsign=false through the test fixture so synthetic git
commits do not hang on local GPG/pinentry configuration. Also disable
attestation through MAIN_CONFIG so tests keep the old can_patatt=false
behavior after patatt becomes an unconditional dependency.

As a drive-by, route the test b4 globals, pytest sentinel, and XDG
env overrides through monkeypatch so each test gets automatic
cleanup.

Add pytest to the CI script.

Signed-off-by: Tamir Duberstein <tamird@kernel.org>
Link: https://patch.msgid.link/20260419-ruff-check-v2-5-089dfb264501@kernel.org
Signed-off-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>