chore(extensions): remove old renderer code

[samuelmaddock]

Description of Change

Remove old renderer code used for JavaScript-based Chrome extensions.

The affected files were removed from the bundle in #23340, but never deleted.

Ref #19447

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• PR title follows semantic commit guidelines
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: none

[release-clerk]

No Release Notes

[miniak]

/trop run backport-to 10-x-y

[trop]

The backport process for this PR has been manually initiated -
sending your commits to "10-x-y"!

[miniak]

/trop run backport-to 11-x-y

[trop]

The backport process for this PR has been manually initiated -
sending your commits to "11-x-y"!

[trop]

I was unable to backport this PR to "10-x-y" cleanly;
you will need to perform this backport manually.

[trop]

I have automatically backported this PR to "11-x-y", please check out #26441

[nornagon]

@miniak Why backport this? it's just a cleanup, I don't think it's doing any harm in older branches.

[miniak]

@nornagon I ran into those dangling files when back-porting the IPC change.