fix(pydeck,pydeck-carto): Fix readthedocs builds

[donmccurdy]

Docs for latest pydeck and pydeck-carto releases are now published, based on this PR:

• pydeck v0.9 — https://deckgl.readthedocs.io/en/latest/index.html
• pydeck-carto v0.2 — https://pydeck-carto.readthedocs.io/en/latest/index.html

Changes:

• Copy active Python module to root directory before readthedocs build process
• Pin and install sphinx theme
• Skip broken Jupyter widget build, not required for docs
• Remove binding/pydeck/pyproject.toml (invalid?) during documentation builds
• Update version numbers (from Release: pydeck v0.9.0, pydeck-carto v0.2.0 #8855)

Notes:

I pushed this branch to github today, donmccurdy/pydeck-dev, and this time it did appear in the readthedocs dashboard's branch list. From that I was able to change settings in the readthedocs dashboard to deploy from this branch, push changes, and iteratively fix the issues above. I'm not sure why previous branches didn't appear in the dashboard.

After this PR is merged, the active branch in the readthedocs dashboards can be changed back to master.

[coveralls]

coverage: 89.82% (-0.001%) from 89.821%
when pulling 12dd78e on donmccurdy/pydeck-dev
into ff9246e on master.