Update symfony/yaml version constraint to include 8.0

Author: tacman

composer.json

@@ -20,7 +20,7 @@
 	"require": {
 		"php": ">=7.1.0",
 		"ext-json": "*",
-		"symfony/yaml": "^3.4 || ^4 || ^5 || ^6 || ^7.0",
+		"symfony/yaml": "^3.4 || ^4 || ^5 || ^6 || ^7.0 || ^8.0",
 		"justinrainbow/json-schema": "^5.2 || ^6.0"
 	},
 	"require-dev": {