Relax jupyter-packaging build dependency

[tjni]

jupyer-packaging is now on version v0.12.3 and from evidence in #906 and my own experience building this package in nixpkgs, the latest version seems to work.

Perhaps there is a reason to keep it pinned, but I didn't see discussion about it yet from searching so I thought this PR could also be where this is discussed if there are questions about doing this.

[jjstickel]

Likewise, I ran into this limitation of the old-version specification of jupypter-packaging when updating the jupytext package in Macports. I hot-patched the package there to be >=, same as the PR here.

[mwouts]

Hey @tjni , yes you're correct, we do use the latest version of jupyter_packaging to build the package on the CI, and this works fine. To be consistent we could require jupyter_packaging~=0.12.3 everywhere, or remove the version constraint overall. Do you have a preference?

@tjni , @jjstickel will you need a new release following the change?

Below is the list of occurences of jupyter_packaging in the project:

[jjstickel]

@tjni , @jjstickel will you need a new release following the change?

No, not necessarily. The current macports package applies a patch to work around the version number.

[mwouts]

With #1140 the project has been modernized very significantly. We will be using hatchling from now on, so I guess I can close this PR (sorry about not taking it earlier). Thanks