docs: update docs to reflect addition of mutually exclusive attributes - #2057

$ git fetch
$ gh pr checkout 2057
remote: Enumerating objects: 20, done.
remote: Counting objects: 100% (16/16), done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 10 (delta 6), reused 10 (delta 6), pack-reused 0
Unpacking objects: 100% (10/10), 1.92 KiB | 393.00 KiB/s, done.
From github.com:python-gitlab/python-gitlab
 * [new ref]         refs/pull/2057/head -> walterrowe/main
Switched to branch 'walterrowe/main'

$ git rebase origin/main
dropping 48a1b6d16b49a2f1763cbb20eda66820c49fdeae test: add more tests for RequiredOptional -- patch contents already upstream
dropping 7c9d3905669d9b2d456b832e709834a288b7a496 chore(cli): rename "object" to "GitLab resource" -- patch contents already upstream
Successfully rebased and updated refs/heads/walterrowe/main.

$ git push --force-with-lease git@github.com:walterrowe/python-gitlab.git HEAD:main
To github.com:walterrowe/python-gitlab.git
 ! [rejected]        HEAD -> main (stale info)
error: failed to push some refs to 'github.com:walterrowe/python-gitlab.git'

# Normally I use --force-with-lease to make sure I don't break anything.
# But in this case it didn't work. So I then used --force

$ git push --force git@github.com:walterrowe/python-gitlab.git HEAD:main
Enumerating objects: 11, done.
Counting objects: 100% (11/11), done.
Delta compression using up to 8 threads
Compressing objects: 100% (6/6), done.
Writing objects: 100% (6/6), 808 bytes | 808.00 KiB/s, done.
Total 6 (delta 5), reused 0 (delta 0), pack-reused 0
remote: Resolving deltas: 100% (5/5), completed with 5 local objects.
To github.com:walterrowe/python-gitlab.git
 + 16a051a...24b720e HEAD -> main (forced update)