bug#60210: 30.0.50; tab-bar height not recalculated when face changes

[Gabriel do Nascimento Ribeiro]

Steps:

1) emacs -Q (master "ae91da52335aafaff5405a49c23460082dfb460d")

2) Enable tab-bar:

   (tab-bar-mode +1)

3) Change some face attribute of tab-bar to force increase the tab-bar
height, e.g:

   (set-face-attribute 'tab-bar nil :box 4)
   (set-face-attribute 'tab-bar nil :height 1.2)

Result: the new face is displayed and the tab-bar height is properly
adjusted to reflect the new height.

4) Reset face attributes of tab-bar to force original height, e.g.:

   (set-face-attribute 'tab-bar nil :box nil)
   (set-face-attribute 'tab-bar nil :height 1.0)

Result: the new face is displayed, but the tab-bar height is not
properly adjusted to reflect the new height.

---
Gabriel