Fix an API test failure on macOS

[pisv]

What it does

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 #13217.

This fix removes it from the expected object for macOS.

How to test

Run yarn test on macOS.

Review checklist

• [x] As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[msujew]

@JonasHelming Someone on your side available to review this? Neither Jonah nor I have a Mac.

[rschnekenbu]

@msujew We don't have Macs here either.

[tsmaeder]

I have one at home, but I'm not there right now ;-)

[tsmaeder]

@pisv which test suite is this?

[pisv]

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