py-rich-theme-manager: add Python 3.13 subport

[breun]

Description

Add Python 3.13 subport.

Tested on

macOS 15.1.1 24B91 arm64
Xcode 16.1 16B40

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• checked your Portfile with port lint?
• tried existing tests with sudo port test?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?
• checked that the Portfile's most important variants haven't been broken?

[reneeotten]

@breun there are missing dependencies

[breun]

I'll rerun the jobs when those are merged. I expected them to be merged quickly, but GitHub Actions seems very slow recently.

[reneeotten]

@breun you need to do a “rebase” as not to get merge commits

[breun]

@reneeotten I'm used to working with GitLab, where I can type /rebase and it's all done. I found a button in the GitHub UI to 'sync' the branch, but apparently that did a merge instead of a rebase. Do you know if GitHub provides a way to rebase a branch, or does it need to be done manually locally?

[breun]

I think I'll just redo this PR as well, the Python 3.8 subport also needs to be removed because py38-rich was removed.

[reneeotten]

Best advice is to use the command line instead of the GitHub web interface

[breun]

Second attempt: #27022

[reneeotten]

or you can do a "squash-and-merge" and update the commit message from the interface.