drop gpui x11 backend (wayland-only)

Author: phisch

.github/workflows/release.yml

@@ -22,7 +22,6 @@ jobs:
             pkg-config \
             libwayland-dev \
             libxkbcommon-dev \
-            libxkbcommon-x11-dev \
             libfontconfig1-dev \
             libsystemd-dev