Bump serialize-javascript from 1.5.0 to 4.0.0 in /ClientOnly

Bumps [serialize-javascript](https://github.com/yahoo/serialize-javascript) from 1.5.0 to 4.0.0.
- [Release notes](https://github.com/yahoo/serialize-javascript/releases)
- [Commits](yahoo/serialize-javascript@v1.5.0...v4.0.0)

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