remotes/: Remove tarballs for weston > 10.0.0

Weston 10.0.0 was the last release which points to
wayland.freedesktop.org for downloading the tarballs. Starting with
10.0.1 all the tarballs have links for
gitlab.freedesktop.org/wayland/weston.

Remove them as they aren't referenced anywhere.

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>