Bump freesasa from 2.1.0 to 2.2.1

Bumps [freesasa](https://github.com/mittinatten/freesasa) from 2.1.0 to 2.2.1.
- [Release notes](https://github.com/mittinatten/freesasa/releases)
- [Changelog](https://github.com/mittinatten/freesasa/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mittinatten/freesasa/commits)

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

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

setup.py

@@ -49,7 +49,7 @@
         'torchsummary',
         'torch',
         'pdb2sql >= 0.5.0',
-        'freesasa==2.1.0;platform_system=="Linux"',
+        'freesasa==2.2.1;platform_system=="Linux"',
         'freesasa==2.1.0;platform_system=="Darwin"'
         ],
     extras_require={