Bump greenlet from 2.0.1 to 3.1.1

Bumps [greenlet](https://github.com/python-greenlet/greenlet) from 2.0.1 to 3.1.1.
- [Changelog](https://github.com/python-greenlet/greenlet/blob/master/CHANGES.rst)
- [Commits](python-greenlet/greenlet@2.0.1...3.1.1)

---
updated-dependencies:
- dependency-name: greenlet
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements.txt

@@ -16,7 +16,7 @@ Flask-Mail==0.9.1
 Flask-Migrate==4.0.0
 Flask-RESTful==0.3.9
 Flask-SQLAlchemy==2.5.1
-greenlet==2.0.1
+greenlet==3.1.1
 gunicorn==20.1.0
 idna==2.10
 itsdangerous==2.0.1