Update to stable php-tuf releases

We're already on 2.0.0, which probably happened in a general composer dependencies issue. However, noticed we can increase the constraint to 2.0.0 whereas it was previously an rc, so added an MR for that.

Seems pretty straightforward, didn't break anything.

Merge conflict in composer.lock.

longwave → closed merge request !11067

In fact it was easy to resolve (didn't need resolving at all!) so let's just land this.

Committed 616d104 and pushed to 11.x. Thanks!

Automatically closed - issue fixed for 2 weeks with no activity.