Remove flux dependency (#10313)

src/hooks/useDispatcher.ts

@@ -15,15 +15,12 @@ limitations under the License.
 */
 
 import { useEffect, useRef } from "react";
-import { Dispatcher } from "flux";
 
 import { ActionPayload } from "../dispatcher/payloads";
+import { MatrixDispatcher } from "../dispatcher/dispatcher";
 
-// Hook to simplify listening to flux dispatches
-export const useDispatcher = (
-    dispatcher: Dispatcher<ActionPayload>,
-    handler: (payload: ActionPayload) => void,
-): void => {
+// Hook to simplify listening to event dispatches
+export const useDispatcher = (dispatcher: MatrixDispatcher, handler: (payload: ActionPayload) => void): void => {
     // Create a ref that stores handler
     const savedHandler = useRef((payload: ActionPayload) => {});