Update composer.json updated to use main branch.

composer.json

@@ -6,7 +6,7 @@
     "repositories": [
         {
             "type": "composer",
-            "url": "https://git.uwaterloo.ca/wcms/wcms-packages/raw/8.x-1.x/packages.json"
+            "url": "https://git.uwaterloo.ca/wcms/wcms-packages/raw/main/packages.json"
         }
     ],