LibWeb: Implement navigator.clipboard.readText

Author: https://github.com/trflynn89
Commit: a1985e57e7
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4548
Reviewed-by: https://github.com/shannonbooth

Libraries/LibWeb/Clipboard/Clipboard.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, Tim Flynn <trflynn89@serenityos.org>
+ * Copyright (c) 2023-2025, Tim Flynn <trflynn89@ladybird.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -23,6 +23,8 @@ public:
     static WebIDL::ExceptionOr<GC::Ref<Clipboard>> construct_impl(JS::Realm&);
     virtual ~Clipboard() override;
 
+    GC::Ref<WebIDL::Promise> read_text();
+
     GC::Ref<WebIDL::Promise> write_text(String);
 
 private: