Bump prettier from 2.6.2 to 2.8.7 in /desktop

Summary: Updates prettier and applies the fixes.

Reviewed By: antonk52

Differential Revision: D45087515

fbshipit-source-id: 226814ab4805eb12e64c2134407164498c708c0a

desktop/flipper-plugin/src/ui/Dialog.tsx

@@ -160,7 +160,7 @@ export const Dialog = {
     message: React.ReactNode;
     type: 'info' | 'error' | 'warning' | 'success';
   } & BaseDialogOptions): Promise<void> & {close(): void} {
-    let modalRef: ReturnType<typeof Modal['info']>;
+    let modalRef: ReturnType<(typeof Modal)['info']>;
     return Object.assign(
       new Promise<void>((resolve) => {
         modalRef = Modal[type]({

desktop/flipper-plugin/src/ui/theme.tsx

@@ -70,7 +70,7 @@ export const theme = {
 } as const;
 
 export type Spacing =
-  | keyof typeof theme['space']
+  | keyof (typeof theme)['space']
   | number
   | undefined
   | boolean;