Fix tests failing after upgrading the editor to `v41.2.1`

[filipsobol]

Some tests started to fail after upgrading the editor to version 41.2.1. We've decided to ignore these errors for now and create this issue as a reminder to fix them, because it could cause delay of the release including new installation methods.

The version 41.2.1 was released about 3 months ago and it doesn't seem to cause any issues so far.

Please look for TODO comments in the code including this PR number.

[filipsobol]

ckeditor5-angular/src/ckeditor/ckeditor.component.spec.ts

Lines 411 to 412 in 711aae3

	// TODO: https://github.com/ckeditor/ckeditor5-angular/issues/420
	// expect( error2Spy ).toHaveBeenCalledTimes( 0 );