Speed up RTD env generation

[mikemhenry]

Description

Motivation and context

Resolves #???

How has this been tested?

Change log

[mikemhenry]

This should speed up our RTD builds!

[ijpulidos]

Getting invalid option even though it is following the documentation at https://docs.readthedocs.io/en/stable/guides/conda.html#making-builds-faster-with-mamba Problem in your project's configuration. Invalid "build.tools.python": readthedocs.yml: Invalid configuration option: build.tools.python. Make sure the key name is correct. Maybe we want the conda: field in the yaml to be after the build.tools.python ? :shrug:

[codecov[bot]]

Codecov Report

Merging #1105 (4e36a6b) into main (4e36a6b) will not change coverage. The diff coverage is n/a.

:exclamation: Current head 4e36a6b differs from pull request most recent head 83833b3. Consider uploading reports for the commit 83833b3 to get more accurate results

[mikemhenry]

I was surprised this didn't work since it is the same as it is here? https://github.com/choderalab/openmmtools/blob/main/readthedocs.yml maybe I am missing something @ijpulidos

[mikemhenry]

@ijpulidos should be good to go now!