Update readthedocs.yaml

[asonnenschein]

Related Issue(s):

Closes #

DND-1259

Proposed Changes:

For inclusion in changelog (if applicable):

1. N/A

Not intended for changelog:

1. N/A

Diff of User Interface

Old behavior: readthedocs.yaml is out of date and missing build os.

New behavior: readthedocs.yaml is updated with build os.

PR Checklist:

• [] This PR is as small and focused as possible
• [] If this PR includes proposed changes for inclusion in the changelog, the title of this PR summarizes those changes and is ready for inclusion in the Changelog.
• [] I have updated docstrings for function changes and docs in the 'docs' folder for user interface / behavior changes
• [] This PR does not break any examples or I have updated them

(Optional) @mentions for Notifications: