Config fields get populated in JSON config even if not displayed
### Describe The Bug

When creating a config schema, you can use the `condition` property to show or hide a field based on the value of another field.

For example, let's say that I have an iPad that may or may not have cellular capability.
In the config schema I add a required checkbox (boolean) field named `hasCellular`.
Then I add a non-required textbox (string) field named `phoneNumber`, with condition `"return model.devices[arrayIndices].hasCellular === true;"`
```
    ...
    "hasCellular": {
        "title": "iPad Has Cellular Capabilities",
        "type": "boolean",
        "required": true
    },
    "phoneNumber": {
        "title": "Phone Number",
        "type": "string",
        "required": false,
        "condition": {
            "functionBody": "return model.devices[arrayIndices].hasCellular === true;"
        }
    },
    ...
```

In Config UI, I go ahead and configure in the Plugin Config window an iPad that has cellular:

- I tick the `hasCellular` checkbox, and the field `phoneNumber` is displayed.
- I enter the value `0123456789` in field `phoneNumber`.

Then I realize my mistake: this iPad does not have cellular capability! So I uncheck `hasCellular` and the the field `phoneNumber` is hidden. I click the Save button.
If in Config UI, I go to Settings -> General -> JSON Config and look at the json, it will show:
```
  ...
  "hasCellular": false,
  "phoneNumber": "0123456789",
...
```
While this is a valid configuration per the schema, it logically makes no sense. My expectation would be that if the field `phoneNumber` is not displayed, then it is not part of the configuration of this device, therefore it would not appear in the json.

### Logs

_No response_

### Config

_No response_

### Homebridge UI Version

4.62.0

### Homebridge Version

1.8.4

### Node.js Version

22.9.0

### Operating System

macOS

### Environment Info

Using hb-service

### Raspberry Pi Model

None