Fix typo in role hierarchy docs

Closes gh-10804

docs/modules/ROOT/pages/servlet/authorization/architecture.adoc

@@ -201,7 +201,7 @@ AccessDecisionVoter hierarchyVoter() {
     hierarchy.setHierarchy("ROLE_ADMIN > ROLE_STAFF\n" +
             "ROLE_STAFF > ROLE_USER\n" +
             "ROLE_USER > ROLE_GUEST");
-    return new RoleHierarcyVoter(hierarchy);
+    return new RoleHierarchyVoter(hierarchy);
 }
 ----