fix: handle unclosed string literal for multiline vue component props

[hi-ogawa]

Description

• Closes Multiline Vue component props breaks import.meta.env vitest-dev/vitest#5387

It looks like js-token cannot perfectly handle extreme Vue input and some people are experiencing issues on Vitest since is-token version is introduced in Vitest 1.3.0.

The example I added here changes the source length in current version and it makes Vitest's import.meta.env => __vite_ssr_import_meta__.env replacement to miss the spot of the original code.

  <SomeOtherComponent
    :some-prop="
      testValue
        ? 'A long value to break handling of env variables'
        : 'it needs to break into a new line'
    "
  >

  <SomeOtherComponent
    :some-prop=""  <--- doubled double quote
      testValue
        ? '                                               '
        : '                                 '
    ""
  >

js-token detects the original double quote as "unclosed string literal" https://github.com/lydell/js-tokens?tab=readme-ov-file#stringliteral like below. In this case, I think we can just keep the output and it looks working now.

  { type: 'StringLiteral', value: '"', closed: false },

I checked with the previous regex version in the first commit 641b7a1 and it's working similar, so probably regex version has been saving vue input magically.