python2 `ruamel_yaml` is still required by some scipts

[algent-al]

Noticed today after reinstalling the system and following the docs.

task publish
task: [run-safety-catches] /home/algent/Repository/getsolus/packages/common/Scripts/package-publish-safety-catches.sh
task: [publish] git push
Enumerating objects: 15, done.
Counting objects: 100% (15/15), done.
Delta compression using up to 20 threads
Compressing objects: 100% (8/8), done.
Writing objects: 100% (8/8), 1.43 KiB | 1.43 MiB/s, done.
Total 8 (delta 6), reused 0 (delta 0), pack-reused 0 (from 0)
remote: Resolving deltas: 100% (6/6), completed with 6 local objects.
remote: Bypassed rule violations for refs/heads/main:
remote: 
remote: - Changes must be made through a pull request.
remote: 
To github.com:getsolus/packages.git
   4b8d1f5223..5e34e8294d  main -> main
Traceback (most recent call last):
  File "/home/algent/Repository/getsolus/packages/common/Scripts/gettag.py", line 16, in <module>
    from ruamel.yaml import YAML
ModuleNotFoundError: No module named 'ruamel'
task: Failed to run task "publish": task: Command "if [ -f package.yml ]; then /home/algent/Repository/getsolus/packages/common/Scripts/gettag.py /home/algent/Repository/getsolus/packages/packages/b/broot/package.yml; fi" failed: exit status 1

ruamel_yaml used to be a dependency of py2 ypkg. But now it is still required by common/Scripts/gettag.py in orded to publish an update.

[davidjharder]

We don't document functions that require Staff privileges on the help center

[davidjharder]

Added to private Staff docs