fix(dropdowns): fix ResizeObserver loop error

What does this MR do?

fix(dropdowns): fix ResizeObserver loop error

This rewrites a previous fix that meant to address an unexpected scrolling issue but ended up causing a ResizeObserver loop error. While the error is harmless, it does cause an error overlay to show up in the GDK, and sends events to our Sentry instance in production. This applies the simpler fix that was outlined in !3484 (merged) which seems to fix both issues.

Re gitlab#415039 (closed)

Repro steps

1. In the GDK, checkout the master branch and run yarn.
2. In a short window, try opening the context switcher. It should open properly, but an error overlay should be displayed.
3. Checkout the integration branch from gitlab!123422 (closed) and run yarn again.
4. Repeat step 2. Not error overlay should appear.
5. Navigate to a tall page that has dropdowns toward the bottom, the notification settings for example. Scroll down to one of the last dropdowns and open it. The sroll position within the page should not change.

Screenshots or screen recordings

Before this change, opening the context switcher could cause a ResizeObserver loop error in shorter windows.

Before	After
	No error

Integration merge requests

• GitLab: mr_url
• CustomersDot: mr_url
• Status Page: mr_url

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