Tree Sitter: Use Tree Sitter for highlighting in the chunk generator.
Review Request #14524 — Created July 28, 2025 and updated — Latest diff uploaded
This change makes it so we attempt to use tree sitter (if available) for
diffs. If the tree sitter highlighting is unavailable (for example, we
don't have a matching grammar), or fails for some reason, we'll then
fall back on Pygments.
- Ran unit tests.
- Viewed a variety of diffs of different file types and verified that
the new highlighting worked correctly.