1.5-dev: Page labels overflow on Windows

Summary:

Page labels seem to be too big, and overflow their black background which they should be inside of. Only observed on Windows, Fedora local build does not have this issue.

Steps to reproduce:

• open Inkscape
• open the contest winner from https://inkscape.org/\\\~Denis_Kuznetsky/%E2%98%85isometric-madness

What happened?

What should have happened?

No overflow.

Version info

Inkscape 1.5-dev (6988912, 2026-04-20, custom)

                      Compile  (Run)
    GLib version:     2.86.3
    GTK version:      4.20.3 (4.20.3)
    glibmm version:   2.86.0
    gtkmm version:    4.20.0
    libxml2 version:  2.15.1
    libxslt version:  1.1.45
    Cairo version:    1.18.4 (1.18.4)
    Pango version:    1.56.4 (1.56.4)
    HarfBuzz version: 12.3.0 (12.3.0)
    Poppler version:  25.12.0

    OS version:       Windows 10 22H2