This PR removes some default language settings that are now provided by
their respective extensions.

In #10296 we added the ability for the language configuration within
extensions to provide certain language settings (e.g., `tab_size`).

New versions of the extensions have been published that take advantage
of that and have been in circulation for over a month now. To that end,
we no longer need these settings provided as defaults.

Release Notes:

- N/A