x11-toolkits/wlroots-devel: update to 0.16.0

Changes: https://gitlab.freedesktop.org/wlroots/wlroots/-/compare/a75f9be2e...0.16.0
(cherry picked from commit 5f3f417591177151176e34a21ff9b1fb51f5c01b)
(cherry picked from commit 3e2508cb6a64309206f5ad214d682a75d1deca0e)
(cherry picked from commit 681552e99985390695ef1536978e73eb241c81ad)
(cherry picked from commit 680b51255d656d3c2c58ed4b249ca8339f9d8fb9)
(cherry picked from commit 5d779e19726713aebe1bb607106954b4ee52386d)