Preserve comments when auto-updating `deno.jsonc`

[injust]

It would be great if fresh's auto-updater could preserve comments in deno.jsonc.

This seems to be a known limitation (see https://github.com/denoland/fresh/issues/1576).

[epangelias]

I am guessing its because https://jsr.io/@std/jsonc doesn't support serialization yet