Fixed file template dropdown for the "New File" editor for smaller/zoomed screens

What does this MR do?

Fixes the dropdown issue on zoomed/smaller screens

Are there points in the code the reviewer needs to double check?

Until what point do we consider not supporting a certain screen size / zoom level

Why was this MR needed?

To fix the dropdown position when zooming in on the screen

Screenshots (if relevant)

Zoom levels

100% Zoom

175% Zoom

200% Zoom

300% Zoom

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #23962 (closed)

Affected pages for the modified css-classes

./app/assets/stylesheets/pages/editor.scss: .gitignore-selector, ./app/assets/stylesheets/pages/editor.scss: .license-selector, ./app/assets/stylesheets/pages/editor.scss: .gitlab-ci-yml-selector { ./app/views/projects/blob/_editor.html.haml: .gitlab-ci-yml-selector.js-gitlab-ci-yml-selector-wrap.hidden ./app/assets/stylesheets/pages/editor.scss: .new-file-name { ./app/views/projects/blob/_editor.html.haml: required: true, class: 'form-control new-file-name'