Limit BufferSnapshot::surrounding_word search to 256 characters (#32016)

This is the first step to closing #16120. Part of the problem was that
`surrounding_word` would search the whole line for matches with no
limit.

Co-authored-by: Conrad Irwin \<conrad@zed.dev\>
Co-authored-by: Ben Kunkle \<ben@zed.dev\>
Co-authored-by: Cole Miller \<cole@zed.dev\>

Release Notes:

- N/A
81f8e2ed4aAnthony Eid committed on 6/3/2025, 9:08:59 PM· committed by GitHubparentb9256dd
1 file changedLine totals unavailable