Spring Update MockCookie to make use of Servlet 6.0 APIs and semantics for "attributes"

Modified MockCookie to populate attributes using setAttribute.

Comment From: sbrannen

This has been merged into main in 281736f14eba93ea7bfe67ae7f349a338660ed71 and revised in d1d2d5943e181d3aaaacb5c79d6e6dc3a0c02bbc, f9cb0eba8702ceb2f1bf100355a2b11394b944c5, and 9fb61c57ae6dc04cbcea4a0785da2c1b7a8b5a33.

Thanks