[url_launcher] Adds lint ignores to the usage of RouteInformation.location

Author: chunhtai

packages/url_launcher/url_launcher_platform_interface/test/link_test.dart

@@ -83,6 +83,10 @@ class _RouteDelegate extends RouterDelegate<RouteInformation>
     if (_history.isEmpty) {
       return const Placeholder(key: Key('empty'));
     }
+    // TODO(chunhtai): remove the ignore once the following line can migrate to
+    // use RouteInformation.uri after the issue is resolved.
+    // https://github.com/flutter/flutter/issues/100624.
+    // ignore: unnecessary_string_interpolations, deprecated_member_use
     return Placeholder(key: Key('${_history.last.location}'));
   }
 }