try mamba, remove docs job in azure

[bollwyvl]

References

• attempt at https://github.com/krassowski/jupyterlab-lsp/issues/311#issuecomment-671661109

Code changes

• updates and uses mamba instead of conda
• removes docs jobs (because RTD)

User-facing changes

• n/a

Backwards-incompatible changes

• n/a

Chores

• linted
• tested
• documented
  • not sure if we'll want to also recommend this, since we use it?
• changelog entry

[bollwyvl]

before	after

[bollwyvl]

Hah, windows still failing, will try pinning conda (looks line conda-forge maybe jumped the gun with 4.8.4)

[bollwyvl]

before	after

yeah, so looks like a minute across the board (still-running job flaked). Not bad! I've tried pinning conda, and telling it not to update incidental packages, will see if that offsets the additional expense of mamba and friends (or makes it worse).

[bollwyvl]

Still fail on windows, but got further. interesting that our huge solve actually went slower, but there's so many factors...

before	after

[bollwyvl]

The tea laves (win/36) suggest we're saving a couple minutes on windows, which makes sense. So we can either:

• merge this now, just rely on those gains for future stuff
• see how some other approaches (like conda-lock) work, in isolation (as it would become less reliant on runtime solves)

before	after

[krassowski]

Yes, this seems like a step in the right direction. Feel free to merge or explore other options! I do have high hopes for GitHub Actions.

[bollwyvl]

Welp, it's easy to back out, and making subsequent experimentation faster is just, well, faster!