graphics/wayland: update to 1.21.0

Changes: https://lists.freedesktop.org/archives/wayland-devel/2022-June/042268.html
PR: 264980
Reported by: Phoronix, Repology
Approved by: manu

(cherry picked from commit 43f75e9cd9a2d432033ed85dba9a2eb17aaaad4c)