Make tb-dev worktree-compatible

tb-dev initial check on git-root prevents it to be used in valid tor-browser working tree directories unless they're named exactly tor-browser.

Let's fix this.

added All Platforms Bug labels

assigned to @ma1

marked this issue as related to #41803 (closed)

changed the description

mentioned in merge request !982 (merged)

added Build System Doing labels

closed

removed Doing label

marked this issue as related to tor-browser-build#41113 (closed)