[Contracts] add branch-aliases for dev-main

Author: nicolas-grekas

composer.json

@@ -32,6 +32,9 @@
         }
     },
     "extra": {
-        "branch-version": "1.1"
+        "branch-version": "1.1",
+        "branch-alias": {
+            "dev-main": "1.1-dev"
+        }
     }
 }