IWYU: usage of std::optional requires include in card_unmask_challenge_option.h

Bug: 41455655
Change-Id: I3b0e74b83fed9ae13431b217017dde05fee50d14
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5556726


Reviewed-by: Colin Blundell <blundell@chromium.org>
Commit-Queue: José Dapena Paz <jdapena@igalia.com>
Cr-Commit-Position: refs/heads/main@{#1304295}