Bump astropy-healpix from 1.0.2 to 1.0.3

Bumps [astropy-healpix](https://github.com/astropy/astropy-healpix) from 1.0.2 to 1.0.3.
- [Changelog](https://github.com/astropy/astropy-healpix/blob/v1.0.3/CHANGES.rst)
- [Commits](astropy/astropy-healpix@v1.0.2...v1.0.3)

---
updated-dependencies:
- dependency-name: astropy-healpix
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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