Bump serialize-javascript in /web/wp-content/plugins/buttons-with-expiry

Bumps [serialize-javascript](https://github.com/yahoo/serialize-javascript) from 6.0.0 to 6.0.2.
- [Release notes](https://github.com/yahoo/serialize-javascript/releases)
- [Commits](yahoo/serialize-javascript@v6.0.0...v6.0.2)

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

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