ASF Pelican update plan

Here is an outline of an update plan for Pelican.

1. Improve and update pip requirements setup.
- #20
- #399
- #636
2. Convert to a modern uv installation.
- #92
- #702
4. See if cmarkgfm package replaces libcmark
- #610
- #69
- #71
- #400
6. Stash pelican setup and use stack for quick builds.
- #51
- #56 (?)

#45 may be done at any point or afterwards