Add supportsFlight flag to indicate that this DevTools Supports Flight Clients

Author: sebmarkbage

packages/react-devtools-shared/src/hook.js

@@ -564,6 +564,9 @@ export function installHook(target: any): DevToolsHook | null {
     // React v16 checks the hook for this to ensure DevTools is new enough.
     supportsFiber: true,
 
+    // React Flight Client checks the hook for this to ensure DevTools is new enough.
+    supportsFlight: true,
+
     // React calls these methods.
     checkDCE,
     onCommitFiberUnmount,