[Security] Keep SymfonyCasts as backers of the Security components 🤗

Author: nicolas-grekas

README.md

@@ -6,10 +6,6 @@ The Notifier component sends notifications via one or more channels (email, SMS,
 Sponsor
 -------
 
-The Notifier component for Symfony 7.2 is [backed][1] by:
-
- * [Sweego][2], a European email and SMS sending platform for developers and product builders. Easily create, deliver, and monitor your emails and notifications.
-
 Help Symfony by [sponsoring][3] its development!
 
 Resources
@@ -21,6 +17,4 @@ Resources
    [send Pull Requests](https://github.com/symfony/symfony/pulls)
    in the [main Symfony repository](https://github.com/symfony/symfony)
 
-[1]: https://symfony.com/backers
-[2]: https://www.sweego.io/
 [3]: https://symfony.com/sponsor