Labels dropdown on Work Items is empty on smaller viewports

Summary

The labels dropdown on Work Items shows nothing when dropped-up instead of down.

Steps to reproduce

1. Open any task.
2. Shorten the viewport (or otherwise force a dropup, instead of a dropdown).
3. Click 'edit' on the labels widget.
4. Observe an empty/incomplete drop-up (even when filtering).

Example Project

Any Work Item, currently.

What is the current bug behavior?

The dropup is empty and looks incomplete.

What is the expected correct behavior?

The user can select from the list of labels, as normal.

Relevant logs and/or screenshots

Screen_Recording_2024-05-07_at_10.44.20

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of: \\\`sudo gitlab-rake gitlab:env:info\\\`) (For installations from source run and paste the output of: \\\`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production\\\`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of: \`sudo gitlab-rake gitlab:check SANITIZE=true\`) (For installations from source run and paste the output of: \`sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true\`) (we will only investigate if the tests are passing)

Possible fixes