"Your Firefox is critically out of date" banner

When running an up-to-date version of Tor, I'm sometimes prompted with a banner which says:

"Your Firefox is critically out of date. An update is required to stay secure. (Button: Update Now)"

This is a piece of Firefox code that should be disabled, so users will use the Tor update flow instead of being prompted to install Firefox.

Trac:
Username: hellomebois