AI Explain Code: when getting large selections explained the UI becomes unusable
### Summary
When I attempt to get a large select explained (e.g. all of https://staging.gitlab.com/source-code-management-test-group/source-code-management-test-project/-/blob/main/ee/lib/sidebars/groups/menus/security_compliance_menu.rb) The pop-up AI feature becomes so large that I can't see the top or bottom and I also can't scroll:

### Example Project
https://staging.gitlab.com/source-code-management-test-group/source-code-management-test-project/-/blob/main/ee/lib/sidebars/groups/menus/security_compliance_menu.rb
### What is the current *bug* behavior?
<!-- Describe what actually happens. -->
### What is the expected *correct* behavior?
<!-- Describe what you should see instead. -->
### Relevant logs and/or screenshots
Using Chrome
In Staging
### Output of checks
<!-- If you are reporting a bug on GitLab.com, uncomment below -->
<!-- This bug happens on GitLab.com -->
<!-- /label ~"reproduced on GitLab.com" -->
#### Results of GitLab environment info
<!-- Input any relevant GitLab environment information if needed. -->
<details>
<summary>Expand for output related to GitLab environment info</summary>
<pre>
(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`)
</pre>
</details>
#### Results of GitLab application Check
<!-- Input any relevant GitLab application check information if needed. -->
<details>
<summary>Expand for output related to the GitLab application check</summary>
<pre>
(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)
</pre>
</details>
### Possible fixes
<!-- If you can, link to the line of code that might be responsible for the problem. -->
issue