Bump pillow from 7.1.2 to 8.1.1

Bumps [pillow](https://github.com/python-pillow/Pillow) from 7.1.2 to 8.1.1.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst)
- [Commits](python-pillow/Pillow@7.1.2...8.1.1)

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

Author: dependabot[bot]

requirements.txt

@@ -28,7 +28,7 @@ msgpack==0.6.2
 openapi-codec==1.3.2
 packaging==20.3
 pep517==0.8.2
-Pillow==8.0.0
+Pillow==8.1.1
 progress==1.5
 psycopg2-binary==2.8.6
 pycparser==2.20