Snapshot tests recently started reporting this warning:
> Snapshot test passes but the existing value is in a legacy format.
> Please run cargo insta test --force-update-snapshots to update to a
> newer format.
This PR is the result of that forced update.
One file (crates/ruff_db/src/diagnostic/render/full.rs) seems to get
corrupted, because it contains strings with unprintable characters that
trigger some bug in cargo-insta. I've manually reverted that file, and
also manually reverted the `input_file:` lines, which we like.
## Summary
Closes#11914.
This PR introduces a snapshot test that replays the LSP requests made
during a document formatting request, and confirms that the notebook
document is updated in the expected way.
