fix: make i18n test failure message easier to read

test/i18n.js

@@ -163,7 +163,7 @@ describe('i18n', () => {
 						assert.strictEqual(
 							sourceKeys.length,
 							translationKeys.length,
-							`Extra keys found in namespace ${namespace.slice(1, -5)} for language "${language}"`
+							`Extra keys found in namespace "${namespace.slice(1, -5)}" for language "${language}"`
 						);
 					});
 				});