Bumps `smile-core.version` from 4.4.0 to 5.2.1.

Updates `com.github.haifengl:smile-core` from 4.4.0 to 5.2.1
- [Release notes](https://github.com/haifengl/smile/releases)
- [Commits](haifengl/smile@v4.4.0...v5.2.1)

Updates `com.github.haifengl:smile-plot` from 4.4.0 to 5.2.1
- [Release notes](https://github.com/haifengl/smile/releases)
- [Commits](haifengl/smile@v4.4.0...v5.2.1)

---
updated-dependencies:
- dependency-name: com.github.haifengl:smile-core
  dependency-version: 5.2.1
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: com.github.haifengl:smile-plot
  dependency-version: 5.2.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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