Bump astropy from 4.2.1 to 4.3.1

Bumps [astropy](https://github.com/astropy/astropy) from 4.2.1 to 4.3.1.
- [Release notes](https://github.com/astropy/astropy/releases)
- [Changelog](https://github.com/astropy/astropy/blob/main/docs/changelog.rst)
- [Commits](astropy/astropy@v4.2.1...v4.3.1)

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

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

requirements.txt

@@ -4,7 +4,7 @@ ampel-interface==0.7.1
 ampel-photometry==0.7.1
 ampel-ztf==0.7.4
 astrobject==0.8.6
-astropy==4.2.1
+astropy==4.3.1
 astropy_healpix==0.6
 backoff==1.11.1
 bs4==0.0.1

setup.py

@@ -29,7 +29,7 @@
         "ampel-photometry == 0.7.1",
         "ampel-ztf == 0.7.4",
         "astrobject == 0.8.6",
-        "astropy == 4.2.1",
+        "astropy == 4.3.1",
         "astropy_healpix == 0.6",
         "backoff == 1.11.1",
         "bs4 == 0.0.1",