bug#60297: 30.0.50; tab-bar-mode does not resize tabs without close button

[Protesilaos Stavrou]

Dear maintainers,

The 'tab-bar-mode' can shrink tabs that exceed a certain width (see
'tab-bar-auto-width' and related).  This does not work when
'tab-bar-close-button-show' is set to nil.

In the scratch buffer of 'emacs -Q':

- Evaluate (tab-bar-mode 1)

- The tab shows the name of the buffer.

- Now rename the buffer to something long:
  (rename-buffer "This is a very long title just to test if tabs have a max 
width as expected.")

- The tab does not grow as much as the new name.

- Now disable the close button: (setq tab-bar-close-button-show nil)

- Evaluate again (tab-bar-mode 1)

- The tab is not responding to 'tab-bar-auto-width'.

All the best,
Protesilaos (or simply "Prot")

* * *

In GNU Emacs 30.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
 3.24.35, cairo version 1.17.6) of 2022-12-24 built on kronos
Repository revision: 6c1413d5ef0d1fea639b0d8c83a0c0065d99359b
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101005
System Description: Arch Linux

Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --mandir=/usr/share/man --with-gameuser=:games
 --with-modules --without-libotf --without-m17n-flt --without-gconf
 --with-native-compilation=yes --with-xinput2 --with-x-toolkit=gtk3
 --without-xaw3d --with-sound=no --with-tree-sitter --without-gpm
 --without-compress-install
 '--program-transform-name=s/\([ec]tags\)/\1.emacs/'
 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions
 -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security
 -fstack-clash-protection -fcf-protection'
 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON
LCMS2 LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG
RSVG SECCOMP SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER WEBP
X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB

-- 
Protesilaos Stavrou
https://protesilaos.com