Data: Registry - check for window (#9261)

* Data: Registry - check for window

The registry code is blindly deferencing window, which will fail if ever
run in node for test or server-side rendering. This adds a simple check
to ensure window exists before dereferencing.

* Data: Check window type before using

packages/data/src/registry.js

@@ -140,7 +140,7 @@ export function createRegistry( storeConfigs = {} ) {
 	 */
 	function registerReducer( reducerKey, reducer ) {
 		const enhancers = [];
-		if ( window.__REDUX_DEVTOOLS_EXTENSION__ ) {
+		if ( typeof window !== 'undefined' && window.__REDUX_DEVTOOLS_EXTENSION__ ) {
 			enhancers.push( window.__REDUX_DEVTOOLS_EXTENSION__( { name: reducerKey, instanceId: reducerKey } ) );
 		}
 		const store = createStore( reducer, flowRight( enhancers ) );