Pre-suppress newly detected variance errors in declare class in xplat (#54620)

Summary:
Pull Request resolved: #54620

Changelog: [Internal]

Reviewed By: marcoww6

Differential Revision: D87550655

fbshipit-source-id: c169abb845de33207eb6e32d43ab146f5c45d9b1

Author: SamChou19815

packages/react-native/flow/dom.js.flow

@@ -1384,6 +1384,7 @@ declare class HTMLCollection<+Elem: HTMLElement> {
   length: number;
   item(nameOrIndex?: any, optionalIndex?: any): Elem | null;
   namedItem(name: string): Elem | null;
+  // $FlowFixMe[incompatible-variance]
   [index: number | string]: Elem;
 }
 

packages/react-native/src/private/webapis/dom/oldstylecollections/HTMLCollection.js.flow

@@ -11,10 +11,12 @@
 import type {ArrayLike} from '../../utils/ArrayLikeUtils';
 
 declare export default class HTMLCollection<+T>
+  // $FlowFixMe[incompatible-variance]
   implements Iterable<T>, ArrayLike<T>
 {
   // This property should've been read-only as well, but Flow doesn't handle
   // read-only indexers correctly (thinks reads are writes and fails).
+  // $FlowFixMe[incompatible-variance]
   [index: number]: T;
   +length: number;
   item(index: number): T | null;

packages/react-native/src/private/webapis/dom/oldstylecollections/NodeList.js.flow

@@ -10,12 +10,15 @@
 
 import type {ArrayLike} from '../../utils/ArrayLikeUtils';
 
+// $FlowFixMe[incompatible-variance]
 declare export default class NodeList<+T> implements Iterable<T>, ArrayLike<T> {
   // This property should've been read-only as well, but Flow doesn't handle
   // read-only indexers correctly (thinks reads are writes and fails).
+  // $FlowFixMe[incompatible-variance]
   [index: number]: T;
   +length: number;
   item(index: number): T | null;
+  // $FlowFixMe[incompatible-variance]
   entries(): Iterator<[number, T]>;
   forEach<ThisType>(
     callbackFn: (value: T, index: number, array: NodeList<T>) => mixed,