Markdown language server unresponsive with large file

Does this issue occur when all extensions are disabled?: Yes

- VS Code Version: 1.121.0
- OS Version: macOS 15.7.7 (24G720)

Steps to Reproduce:

1. Open Activity Monitor or similar.
2. Open https://github.com/llvm/llvm-project/blob/main/llvm/docs/LangRef.md in VSCode.
3. Edit the file.
4. Observe that a `VSCodium Helper (Plugin)` process spins for a minute or so, and the syntax highlighting etc. doesn't update.

I'm guessing there's some exponential blowup somewhere? I tried investigating a bit, it seems that if I remove all `<` and `>` characters from the file, things finish after a second or two instead, that might be a hint?