chore(deps): bump sendgrid from 6.4.7 to 6.4.8

Bumps [sendgrid](https://github.com/sendgrid/sendgrid-python) from 6.4.7 to 6.4.8.
- [Release notes](https://github.com/sendgrid/sendgrid-python/releases)
- [Changelog](https://github.com/sendgrid/sendgrid-python/blob/main/CHANGELOG.md)
- [Commits](sendgrid/sendgrid-python@6.4.7...6.4.8)

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

requirements/common.txt

@@ -61,7 +61,7 @@ eventlet==0.29.1
 gevent==20.9.0
 greenlet==0.4.17 # Required for gevent
 pyyaml==5.3.1
-sendgrid==6.4.7
+sendgrid==6.4.8
 marshmallow==2.15.2
 WeasyPrint==52.1
 Flask-Babel==2.0.0