Fix infinite redrawing/freezing with {centaur,awesome}-tabs

Caused by over-zealous doom-switch-window-hook.

For my own sanity (and if you're curious), I'll break it down here:

1. Doom has a `doom-switch-window-hook` hook. It triggers when window
   focus is changed.
2. We use `buffer-list-update-hook` to trigger
   `doom-switch-window-hook`. (That may sound weird, but this hook is
   reliably executed when window focus is changed -- there are
   safeguards to prevent this from triggering too often)
3. `buffer-list-update-hook` triggers whenever a buffer is created, but
   `doom-switch-window-hook` only triggers if the created buffer is in
   a new window.
4. The use of `with-temp-buffer` in `centaur-tabs-line-format` counts as
   "buffer creation" in a "new window".
5. `+vc-gutter-update-h` is in `doom-switch-window-hook`. This refreshes
   git-gutter, which initiates a redraw of Emacs.
6. When Emacs redraws, it recalculates its mode and header lines. which
   triggers `doom-switch-window-hook` once, which triggers
   `+vc-gutter-update-h`, which redraws the screen, then Emacs recalculates
   the header line, running `centaur-tabs-line-format`...

Infinite loop ensues

Hopefully fixes:
- hlissner/doom-emacs#2436
- ema2159/centaur-tabs#18
- ema2159/centaur-tabs#88

modules/ui/vc-gutter/config.el

@@ -71,7 +71,8 @@ is deferred until the file is saved. Respects `git-gutter:disabled-modes'."
 `doom-escape-hook' hooks."
       (when (and git-gutter-mode
                  (not (memq this-command '(git-gutter:stage-hunk
-                                           git-gutter:revert-hunk))))
+                                           git-gutter:revert-hunk)))
+                 (not inhibit-redisplay))
         (ignore (git-gutter)))))
   ;; update git-gutter when using magit commands
   (advice-add #'magit-stage-file   :after #'+vc-gutter-update-h)