toolchain: Respect currently focused file when querying toolchains (#28875)

Closes #21743


https://github.com/user-attachments/assets/0230f233-58a4-494c-90af-28ce82f9fc1d


Release Notes:

- Virtual environment picker now looks up virtual environment based on
parent directory of active file; this enables having multiple active
virtual environments in a single worktree.
5c2c6d7e5ePiotr Osiewicz committed on 4/16/2025, 5:05:57 PM· committed by GitHubparent4f58bde
6 files changedLine totals unavailable