Add XDG desktop category X-CNC also used by LinuxCNC.

Applied-Upstream: commit:575c5659ae9f52c9614bf1c3648f6014eddeea54
Forwarded: https://github.com/FreeCAD/FreeCAD/pull/10567
Last-Update: 2023-08-04

This ensure FreeCAD and LinuxCNC both show up in the CNC submenu when
both are installed.

Gbp-Pq: Name 0110-desktop-extra-categories.patch

freecad (0.21.2+dfsg1-3) unstable; urgency=medium

  * Team upload.
  * Rework autopkgtest script, update available tests and block
    TestPathApp also for i386.

[dgit import unpatched freecad 0.21.2+dfsg1-3]

Import freecad_0.21.2+dfsg1-3.debian.tar.xz

[dgit import tarball freecad 0.21.2+dfsg1-3 freecad_0.21.2+dfsg1-3.debian.tar.xz]

Import freecad_0.21.2+dfsg1.orig.tar.xz

[dgit import orig freecad_0.21.2+dfsg1.orig.tar.xz]