Ensure /tmp/.X11-unix is in place before starting weston (#6620)

Signed-off-by: Stewart X Addison <[email protected]>

Author: sxa

buildenv/jenkins/JenkinsfileBase

@@ -802,6 +802,7 @@ def runTest( ) {
 			if (env.SPEC.contains('linux') && !(LABEL.contains('ci.agent.dynamic') && CLOUD_PROVIDER == 'azure') && (BUILD_LIST != "external")) {
 				// Detect if Xvfb is on the machine, and if not use the wayland startup code (Initially for EL10)
 				if ( sh(script:"which Xvfb 2>&1", returnStatus:true) != 0 ) {
+					sh "mkdir -p -m 1777 /tmp/.X11-unix"
 					sh "weston --no-config --socket=wayland-vfb --backend=headless-backend.so --xwayland &"
 					env.DISPLAY = ":0"