LSP hangs when requested workspace symbols in a workspace with a large number of files

[lionel-]

Initially reported in posit-dev/positron#9024 by @rmflight.

When a workspace contains a very large amount of files (I tested with a project that has 360719 files), triggering workspace symbols causes the LSP process to consume 100% CPU for a long while. The symbol dialog hangs during that time.

I've reproduced this with the latest version of the quarto extension and an old one 1.116.0.

Screen.Recording.2025-08-27.at.18.26.25.mov