bug#69578: 30.0.50; tab-bar-mode binding of (control tab) not always useful

[Gerd Möllmann]

tab-bar--define-keys makes bindings for TAG like this:

  (unless (global-key-binding [(control tab)])
    (global-set-key [(control tab)] #'tab-next))
  (unless (global-key-binding [(control shift tab)])
    (global-set-key [(control shift tab)] #'tab-previous))
  (unless (global-key-binding [(control shift iso-lefttab)])
    (global-set-key [(control shift iso-lefttab)] #'tab-previous))

These bindings stop taking effect if a mode has its own bindings for
control tab, for instance. A prominent example is Magit.

So, maybe these bindings should not be done?

In GNU Emacs 30.0.50 (build 1, x86_64-apple-darwin23.3.0, NS
 appkit-2487.40 Version 14.3.1 (Build 23D60)) of 2024-03-05 built on
 Pro.fritz.box
Repository revision: a3d7092114db09fee392ccc8187fde03376f2089
Repository branch: HEAD
Windowing system distributor 'Apple', version 10.3.2487
System Description:  macOS 14.3.1