Fix terminal preventing the main section from scrolling

[momesgin]

Summary

Fixes #13036

Technical notes summary

It seems Chrome behaves different from other browsers when the position property is absent on an element that's positioned by its parent's grid layout. Adding position: relative; to the terminal element fixed the scrolling conflict.

Areas or cases that should be tested

#5245 should also be checked

Areas which could experience regressions

I've tested the scrolling and the original loading issue on many different pages while having the terminal open. Please do the same with any page you think it might have loading and scrolling capabilities.

Screenshot/Video

t.mov

Checklist

• The PR is linked to an issue and the linked issue has a Milestone, or no issue is needed
• The PR has a Milestone
• The PR template has been filled out
• The PR has been self reviewed
• The PR has a reviewer assigned
• The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
• The PR has reviewed with UX and tested in light and dark mode, or there are no UX changes

[richard-cox]

The change looks good, however someone who can reproduce the bug should also take a look (i couldn't on linux + chrome)

[codyrancher]

Verified. Working on my end.

it's been already mentioned that the change looks good, it was only waiting for another confirmation to see if the fix works, and Cody confirmed.