fix(plugin-vue): trigger css hmr on custom template languages

[sibbng]

Description

Fix #4588

These changes simply carry mainModule's CSS dependencies into template HMR's affected modules list.

Additional context

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
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• Ideally, include relevant tests that fail without this PR but pass with it.

[mariohamann]

Any change to get that into Vite soon, @Niputi ? :)

[masterkain]

I'd love to see this fixed for this long standing issue with vite / vue / pug / tailwind 👍

[carrrramba]

i've encountered the same problem with vite vanilla js + tailwind jit + handlebars instead of pug. Demo here: https://stackblitz.com/edit/vitejs-vite-acozht?file=index.html

[patak-dev]

@carrrramba please create a new bug report linking to this PR so we can properly track these issues. Thanks!