Upgrade: jupyter-packaging 0.12.3

[slel]

The new release jupyter-packaging 0.12.3
fixes a bug reported at #34421.

• JUPYTER_PACKAGING_SKIP_NPM environment variable versus --skip-npm option jupyter/jupyter-packaging#160
• https://github.com/jupyter/jupyter-packaging/pulls/161
• https://github.com/jupyter/jupyter-packaging/releases/tag/v0.12.3

CC: @slel

Component: packages: standard

Keywords: upgrade, spkg, jupyter_packaging

Author: Samuel Lelièvre

Branch/Commit: 302bf75

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/34432

[slel]

New commits:

302bf75

34432: Upgrade: jupyter-packaging 0.12.3

[slel]

Commit: 302bf75

[slel]

Branch: u/slelievre/34432

[slel]

Author: Samuel Lelièvre

[mkoeppe]

Reviewer: Matthias Koeppe

[vbraun]

Changed branch from u/slelievre/34432 to 302bf75