build(deps): bump rustls in /examples/parachain-example (#1907)

Bumps [rustls](https://github.com/rustls/rustls) from 0.21.10 to 0.23.21.
- [Release notes](https://github.com/rustls/rustls/releases)
- [Changelog](https://github.com/rustls/rustls/blob/main/CHANGELOG.md)
- [Commits](rustls/rustls@v/0.21.10...v/0.23.21)

---
updated-dependencies:
- dependency-name: rustls
  dependency-type: indirect
...

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