Fixes https://github.com/zed-industries/zed/issues/9079

This should fix the arena panic we were observing. I saw that breadcrumb
rendering was on the stack trace for some of the panics, so my suspicion
is that it's being caused by some people navigating into deeply nested
files.

Release Notes:

- Fixed a panic that could occur when displaying too many breadcrumbs.
([#9079](https://github.com/zed-industries/zed/issues/9079))