build(deps): bump serialize-javascript in /demo/vue-cli4

Bumps [serialize-javascript](https://github.com/yahoo/serialize-javascript) from 1.9.1 to 4.0.0.
- [Release notes](https://github.com/yahoo/serialize-javascript/releases)
- [Commits](yahoo/serialize-javascript@v1.9.1...v4.0.0)

---
updated-dependencies:
- dependency-name: serialize-javascript
  dependency-type: indirect
...

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Author: dependabot[bot]