[Contracts] Bump to 2.5 on branch 5.4

Author: nicolas-grekas

composer.json

@@ -28,7 +28,7 @@
  "minimum-stability": "dev",
  "extra": {
  "branch-alias": {
- "dev-main": "2.4-dev"
+ "dev-main": "2.5-dev"
  },
  "thanks": {
  "name": "symfony/contracts",