x11-servers/xorg-server: Update to 21.1.12

Release notes: https://lists.x.org/archives/xorg-announce/2024-April/003499.html

Security: CVE-2024-31080 CVE-2024-31081 CVE-2024-31083
Sponsored by: Beckhoff Automation GmbH & Co. KG

(cherry picked from commit 0df7783381d70c4df74dda76d22425446e09b4c5)