Treesitter commands don't work within injection

[A-Walrus]

Summary

Treesitter commands such as expand, don't work within injected language.
For example say I have a markdown file with some rust code in it and I try to select using treesitter commands, I expect them to act according to the rust syntax tree when I'm within the codeblock.

Reproduction Steps

asciinema

I tried this:

1. Open a markdown file and add a codeblock, for example some rust code.
2. Try to navigate and select within the rust code using treesitter commands.

I expected this to happen:
selection is based on injected rust syntax

Instead, this happened:
selection is based on external markdown syntax

Helix log

No response

Platform

Linux

Terminal Emulator

kgx (Gnome Console)

Helix Version

helix 23.05 (ff442ee)

[the-mikedavis]

Duplicate of #2311

I have some local changes that improve on #5176 that I'm hoping to finish off and push soon.