Pylance not compatible with default editable installs in setuptools>64

[coretl]

https://github.com/microsoft/pyright/blob/main/docs/import-resolution.md#editable-installs

We should do pip install -e . --config-settings editable_mode=compat in the dev container

[coretl]

Strict mode appears to be the future, but it creates a directory of softlinks. This means that clicking through takes you to a soft link, not the file itself, which is annoying. You also need to then set the breakpoint on the link not the original. Workarounds exist:

microsoft/debugpy#1152 (comment)

However I think we should use compat mode for as long as it works...