[fix] kebab case style directives with template causes syntax error

[ghostdevv]

Before submitting the PR, please make sure you do the following

• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
• Prefix your PR title with [feat], [fix], [chore], or [docs].
• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with npm test and lint the project with npm run lint

This fixes #7122 and includes a new test as well

[dummdidumm]

Could you fix the more-dashes case @gtm-nayan mentioned in the conversation and enhance the test for that? Then we're good to go I think.

[ghostdevv]

@dummdidumm yes! Just got a dm from @dominikg about that too 😄

[ghostdevv]

@dummdidumm Should be all fixed now