In certain cases when closing a tab(s), we temporarily lock the width of the tabs instead of letting them grow/shrink. If you close a tab and then quickly collapse a tab group right afterwards, you can end up with the tab group label going into the collapsed state correctly but the tabs in the tab group are still visible.
The issue is that we lock tab sizes on visible tabs using `max-width: ... !important` and we are hiding tabs in collapsed tab groups by using a CSS rule of `max-width: 0`. When we unlock the tab sizes, we only unlock visible tabs, but the tabs inside of the collapsed tab group are no longer considered visible.
This fix removes the tab lock size `max-width: ... !important` rule on all tabs regardless of tab visibility.
Differential Revision: https://phabricator.services.mozilla.com/D233022
4076f2c38a