Schema does not allow actions without arguments in verbose form

### Windows Terminal version (or Windows build number)

1.9.1942.0

### Other Software

_No response_

### Steps to reproduce

Bind any 'shortcut action' using the following syntax:
```
{
"command": {
"action": "toggleAlwaysOnTop" // Most of the toggle actions qualify
},
"keys": "ctrl+alt+shift+§" // Any key combination
}
```

### Expected Behavior

The schema should allow this, it's a working syntax.

### Actual Behavior

It's considered invalid, with two problems:

* > Missing property "delta".
> Arguments corresponding to an Adjust Font Size Action
* > String does not match the pattern of "adjustFontSize".

Start from the Windows Terminal schema validation for shortcut actions and reproduce the issue with the provided toggleAlwaysOnTop command and key binding. Update the schema so an action without arguments is accepted without requiring delta or matching adjustFontSize, then verify that the example no longer reports validation errors.

Written by the indexing model from the issue text.