It's a weird scenario, but evaluating this in 'emacs -Q' will make
characters render more narrowly (and a little shorter) than it did
previously:

(set-face-attribute 'default nil :height 110 :family "Inconsolata_dz")

See the attached screenshot with comparison (master is on the left).

This seems to happen with both Inconsolata_dz which I use and the
original Inconsolata (at least some version of it). The font file which 
I use
resides is linked to at the bottom of 
https://nodnod.net/posts/inconsolata-dz/.

It started to happen right after the changes required to use the
"proportional mode-line" were added. I was kind of waiting for somebody
else to report this problem. ;-( It makes master fairly unusable to me,
however.

Other fonts don't seem to have this effect.

Also, if I first evaluate this form, and then change the :family value
to "Hack", the font changes once (to a font with "normal" width) but
then no subsequent evaluations of this form with other values have any
effect on the used font-family (it is "stuck"), but the window shrinks a
little every time.

In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 
3.24.20, cairo version 1.16.0)
  of 2021-11-11 built on potemkin
Repository revision: ebcba77d4c47ceff24115f80c2109916a6b425b1
Repository branch: scratch/etags-regen
Windowing system distributor 'The X.Org Foundation', version 11.0.12011000
System Description: Ubuntu 20.04.3 LTS