webkit-gtk: Update to 2.36.4

Changes:
2.36.4
======
- Fix the new ATSPI accessibility implementation to add the missing
  Collection interface for the loaded document.
- Fix the MediaSession implementation to make the MPRIS object names more
  sandbox friendly, which plays better with Flatpak and WebKit's own
  Bubblwrap-based sandboxing.
- Fix leaked Web Processes in some particular situations.
- Fix the build with media capture support enabled.
- Fix cross-compilation when targeting 64-bit ARM.
- Fix several crashes and rendering issues.

(leot)