Fix an API test failure on macOS

Before this fix, Monaco API KeybindingService.resolveKeybinding test was failing
on macOS with

```
AssertionError: expected { label: '⌃⇧⌥⌘K', …(6) } to deeply equal { label: '⌃⇧⌥⌘K', …(7) }
+ expected - actual

{
 "WYSIWYG": true
 "ariaLabel": "⌃⇧⌥⌘K"
+  "chord": false
 "dispatchParts": [
   "ctrl+shift+alt+meta+K"
 ]
 "electronAccelerator": "Ctrl+Shift+Alt+Cmd+K"
```

The `chord: false` was removed from the expected object for other platforms
as part of eclipse-theia#13217.

This fix removes it from the expected object for macOS.

examples/api-tests/src/monaco-api.spec.js

@@ -87,7 +87,6 @@ describe('Monaco API', async function () {
                     electronAccelerator: 'Ctrl+Shift+Alt+Cmd+K',
                     userSettingsLabel: 'ctrl+shift+alt+cmd+K',
                     WYSIWYG: true,
-                    chord: false,
                     parts: [new ResolvedChord(
                         true,
                         true,