Bump pooch from 1.5.2 to 1.6.0 (#330)

Bumps [pooch](https://github.com/fatiando/pooch) from 1.5.2 to 1.6.0.
- [Release notes](https://github.com/fatiando/pooch/releases)
- [Changelog](https://github.com/fatiando/pooch/blob/main/doc/changes.rst)
- [Commits](fatiando/pooch@v1.5.2...v1.6.0)

---
updated-dependencies:
- dependency-name: pooch
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>