Add HTML link element attribute values as="{json,script,style}" for modulepreload

[KurtCattiSchmidt]

Summary

This change adds as="style", as="script", and as="json" to the <link rel="modulepreload"> compat data. Chromium is shipping this in 147, so this adds that data as well (see https://chromestatus.com/feature/5202661416763392).

Test results and supporting details

as="script" is the default, and support for this goes back to when each browser originally supported <link rel="modulepreload">. Chrome 147 will begin supporting as="style" and as="json", and Safari recently added support for as="json", in version 26.2 (see "Fixed “text/json/json+json” to be considered an invalid JSON MIME type." note in https://developer.apple.com/documentation/safari-release-notes/safari-26_2-release-notes).

WPT tests reflecting these results:

For Chrome 147 supporting JSON and style modulepreloads, see Experimental results: https://wpt.fyi/results/preload/modulepreload-as.html?label=master&label=experimental&aligned&q=modulepreload-as.html

For Safari 26 supporting JSON modulepreloads, see https://wpt.fyi/results/preload/modulepreload-as.html?label=stable&label=master&aligned

https://chromestatus.com/feature/5202661416763392
https://developer.apple.com/documentation/safari-release-notes/safari-26_2-release-notes

Related issues

[github-actions]

Tip: Review these changes grouped by change (recommended for most PRs), or grouped by feature (for large PRs).

[caugner]

Setting standard_track: true requires providing a spec_url.

In this case, we can to link to https://html.spec.whatwg.org/multipage/links.html#preload-destination for all values.