zink: Only call reapply_color_write if EXT_color_write_enable is available

Allows to use zink with drivers that do not expose this extension.

Backport-to: 23.3 24.0
Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Signed-off-by: Corentin Noël <corentin.noel@collabora.com>
Part-of: <mesa/mesa!27516>