chore: set branch alias to next major version due to BC

Author: mfn

composer.json

@@ -74,7 +74,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "7.x-dev"
+            "dev-master": "8.0-dev"
         },
         "laravel": {
             "providers": [