"not var:abc" does not work as tab_bar_filter #10095

Describe the bug

As tabbar filter, "not var:abc" does not filter out tabs with abc var set.

To Reproduce

1. Launch a new tab with abc var set
2. Update tab_bar_filter to "var:abc", it correctly displays the newly launched tab as well as current active one, but updating it to tab_bar_filter not var:abc, every tab is displayed.