Fix: Do not treat mount points as packages in the empack lock

[martinRenou]

This will help fixing jupyterlite/xeus#237, issue noticed in practice in compiler-research/xeus-cpp#357

This is a breaking change, we should make a major release with it

[martinRenou]

@DerThorsten does it look good to you?

It seems to me it'd be impossible to get the CI green on this PR since:

• it requires an updated pyjs that supports this new entry in the empack lock
• we'd need to release this PR before we can update pyjs

[martinRenou]

emscripten-forge/pyjs#104 for the pyjs fix

emscripten-forge/mambajs#105 for the mambajs fix

[DerThorsten]

@DerThorsten does it look good to you?

It seems to me it'd be impossible to get the CI green on this PR since:

• it requires an updated pyjs that supports this new entry in the empack lock
• we'd need to release this PR before we can update pyjs

jeah, I think its fine to merge things even with breaking the CI.
A CI should help us and not be in our way...so I am fine with whatever is needed ;)

[martinRenou]

So do you think we're good to merge this and make a major release?

[DerThorsten]

So do you think we're good to merge this and make a major release?

Yes