Update sponsors for Symfony 7.3

Author: mttsch

README.md

@@ -17,9 +17,8 @@ Installation
 Sponsor
 -------
 
-Symfony 7.2 is [backed][27] by
-- [Sulu][29]
-- [Rector][30]
+Symfony 7.3 is [backed][27] by
+- [Les-Tilleuls.coop][29]
 
 **Sulu** is the CMS for Symfony developers. It provides pre-built content-management
 features while giving developers the freedom to build, deploy, and maintain custom
@@ -96,5 +95,4 @@ and supported by [Symfony contributors][19].
 [26]: https://symfony.com/book
 [27]: https://symfony.com/backers
 [28]: https://symfony.com/sponsor
-[29]: https://sulu.io
-[30]: https://getrector.com
+[29]: https://les-tilleuls.coop