Update scenario-protected-web-api-verification-scope-app-roles.md

Removed improper use of `cosnt` for instantiated array variable. Replaced with `static readonly`.

Resolves #86545

Author: v-michaelmi

articles/active-directory/develop/scenario-protected-web-api-verification-scope-app-roles.md

@@ -169,7 +169,7 @@ public class TodoListController : Controller
     /// The web API will accept only tokens 1) for users, 2) that have the `access_as_user` scope for
     /// this API.
     /// </summary>
-    const string[] scopeRequiredByApi = new string[] { "access_as_user" };
+    static readonly string[] scopeRequiredByApi = new string[] { "access_as_user" };
 
     // GET: api/values
     [HttpGet]