Bump php-tuf/composer-stager to 2.0.1

Seems straight forward

If it's preferred we can bundle this in to 🐛 [random test failure] PackageUpdateTest::testPackageUpdate Active and commit in one place rather than having two separate issues.

I think it's fine to do in two issues, lessens the chances that another composer update causes commit conflicts with the other issue - at least because I'm committing this right now.

Committed/pushed to 11.x and cherry-picked to 11.1.x, thanks!

catch → closed merge request !11955