Update plotly.js to v4.0.0-rc.0

[emilykl]

Description of change

• Update plotly.js to v4.0.0-rc.0
• Run codegen and regenerate Jupyter js bundles
• Remove all references to mapbox in Plotly Express
• Update tests to remove mapbox references

Note: The failing plotly.js dev build CI job can be ignored. That job runs the tests after pulling dist/plotly.js from the plotly.js master branch, so naturally it will fail since the plotly.js v4.0 changes are not yet on master.

The failing docs build can also be ignored; it will fail until the docs are updated to remove mapbox code, which will be in a separate PR.

[camdecoster]

• Could we update the docs separately to keep things tidy?
• I think we can remove the Stream deprecation warning in _deprecations.py
• I still see a lot of references to linkText/link_text and showLink/show_link. Could those be removed?
• ColorValidator will need to be updated per the v4 changes

[camdecoster]

ColorValidator will need to be updated to remove the references and regex checks for hsv since that got removed. The regex patterns will also need to be updated to match the new color specifier support.

[emilykl]

• Could we update the docs separately to keep things tidy?

Yes, as long as you're OK with the docs build failing on this PR. I'll split the docs changes into a separate PR.

• I think we can remove the Stream deprecation warning in _deprecations.py
• I still see a lot of references to linkText/link_text and showLink/show_link. Could those be removed?
• ColorValidator will need to be updated per the v4 changes

👍 will do, thanks