iinfBox.parse: refactor instanceof to check for type

before
- in iinfBox.parse we would check if result of parseOneBox is instanceof infeBox
- this would fail in case BoxRegistry does not have infeBox, in which case  generic Box would be created with Box.type = 'infe'

after
- cast result of parseOneBox to BoxKind
- check if box.type === 'infe'

src/boxes/iinf.ts

@@ -3,6 +3,7 @@ import { infeBox } from '#/boxes/infe';
 import type { MultiBufferStream } from '#/buffer';
 import { OK } from '#/constants';
 import { Log } from '#/log';
+import type { BoxKind } from '@types';
 
 export class iinfBox extends Box {
   version: number;
@@ -26,9 +27,9 @@ export class iinfBox extends Box {
     for (let i = 0; i < this.entry_count; i++) {
       const ret = parseOneBox(stream, false, this.size - (stream.getPosition() - this.start));
       if (ret.code === OK) {
-        // NEEDS REVIEW:   this was `ret.box.type == 'infe'` before.
-        if (ret.box instanceof infeBox) {
-          this.item_infos[i] = ret.box;
+        const box = ret.box as BoxKind;
+        if (box.type === 'infe') {
+          this.item_infos[i] = box;
         } else {
           Log.error('BoxParser', "Expected 'infe' box, got " + ret.box.type);
         }