Bumps externalauth version to 2.0 for D10 compatibility.

composer.json

@@ -21,6 +21,6 @@
   "require": {
     "rcpl/polaris-api": "2.x-dev",
     "drupal/key": "^1.8",
-    "drupal/externalauth": "^1.1"
+    "drupal/externalauth": "^2.0"
   }
 }