LibWeb: Remove TokenStream::position() and ::rewind_to_position()

Author: https://github.com/AtkinsSJ
Commit: 56e8e0daa1
Pull-request: https://github.com/SerenityOS/serenity/pull/13824

Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp

@@ -114,13 +114,6 @@ void TokenStream<T>::reconsume_current_input_token()
         --m_iterator_offset;
 }
 
-template<typename T>
-void TokenStream<T>::rewind_to_position(int position)
-{
-    VERIFY(position <= m_iterator_offset);
-    m_iterator_offset = position;
-}
-
 template<typename T>
 void TokenStream<T>::skip_whitespace()
 {