Respect multiline lang attributes in syntax highlighting

[matthewp]

Changes

• When lang or type appeared on a later line of a <style> or <script> opening tag, VS Code ignored it and highlighted the embedded content as default CSS or JavaScript. Multiline tags now use the requested Sass, TypeScript, JSON-LD, or other language grammar just like single-line tags. Fixes 🐛 BUG: SASS content incorrectly highlighted as CSS syntax when lang='sass' is not on the same line with <style #14657.
• The TextMate grammar now prescans ordinary opening-tag attributes and applies the language scope when it reaches a complete literal lang or type value. This preserves attribute highlighting without treating dynamic values, unrelated attribute names, or prefixes such as modulex as language selectors.

Testing

• Added multiline Sass and TypeScript grammar fixtures and snapshots covering preceding attributes, default-language fallbacks, JSON-LD and module scripts, quoted and unquoted values, dynamic values, and lookalike attribute names and values.

Docs

• No docs update needed because this corrects syntax highlighting for already-valid <style> and <script> formatting.

[changeset-bot]

🦋 Changeset detected

Latest commit: 1927920

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
astro-vscode	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR