build(deps): bump ndarray from 0.15.1 to 0.15.2

Bumps [ndarray](https://github.com/rust-ndarray/ndarray) from 0.15.1 to 0.15.2.
- [Release notes](https://github.com/rust-ndarray/ndarray/releases)
- [Changelog](https://github.com/rust-ndarray/ndarray/blob/master/RELEASES.md)
- [Commits](rust-ndarray/ndarray@0.15.1...0.15.2)

Signed-off-by: dependabot[bot] <support@github.com>