Remove input source on XR session end (#24269)

Fixes error on 2nd time entering AR: Uncaught DOMException: Failed to execute 'getPose' on 'XRFrame': XRSpace and XRFrame sessions do not match.

src/renderers/webxr/WebXRManager.js

@@ -153,6 +153,8 @@ class WebXRManager extends EventDispatcher {
 
 				if ( inputSource === null ) continue;
 
+				controllerInputSources[ i ] = null;
+
 				controllers[ i ].disconnect( inputSource );
 
 			}