fix(workspaces): don't hide tab-bar on startup

Recent native-comp builds glitch out running in a terminal when
tab-bar-mode is enabled and tab-bar-show is set to nil. I'm not sure if
it's a native-comp specific thing, or just latest emacs-28 dev.

modules/workspaces/siren-tab-bar.el

@@ -58,7 +58,6 @@
   (tab-bar-history-limit 25)
   (tab-bar-new-tab-choice "*scratch*")
   (tab-bar-tab-hints nil)
-  (tab-bar-show nil)
 
   :init
   (defun siren-tab-bar-setup ()