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

Author: nicolas-grekas

README.md

@@ -26,10 +26,6 @@ echo $translator->trans('Hello World!'); // outputs « Bonjour ! »
 Sponsor
 -------
 
-The Translation component for Symfony 7.1 is [backed][1] by:
-
- * [Crowdin][2], a cloud-based localization management software helping teams to go global and stay agile.
-
 Help Symfony by [sponsoring][3] its development!
 
 Resources
@@ -41,6 +37,4 @@ 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://crowdin.com
 [3]: https://symfony.com/sponsor