Bump num-traits from 0.2.14 to 0.2.15 in /light-curve

Bumps [num-traits](https://github.com/rust-num/num-traits) from 0.2.14 to 0.2.15.
- [Release notes](https://github.com/rust-num/num-traits/releases)
- [Changelog](https://github.com/rust-num/num-traits/blob/master/RELEASES.md)
- [Commits](rust-num/num-traits@num-traits-0.2.14...num-traits-0.2.15)

---
updated-dependencies:
- dependency-name: num-traits
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]