chore(deps): update stripe requirement from ~=2.39.0 to ~=2.40.0 (#6588)

Updates the requirements on [stripe](https://github.com/stripe/stripe-python) to permit the latest version.
- [Release notes](https://github.com/stripe/stripe-python/releases)
- [Changelog](https://github.com/stripe/stripe-python/blob/master/CHANGELOG.md)
- [Commits](stripe/stripe-python@v2.39.0...v2.40.0)

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

Author: dependabot-preview[bot]

requirements/common.txt

@@ -27,7 +27,7 @@ SQLAlchemy-Continuum~=1.3.9
 arrow~=0.15.4
 unicode-slugify~=0.1
 bleach~=3.1
-stripe~=2.39.0
+stripe~=2.40.0
 xhtml2pdf~=0.2
 flask-caching~=1.4
 forex-python~=1.5