Update Group-XXXByModel samples to work with 2026 R1

[Tarterman]

It seems something changed in 2026 R1 (and possibly 2025 R3 in certain instances) to where ItemFilter doesn't accept a null value for the propertyFilters anymore. This affects both the Group-CamerasByModel sample and Group-DevicesByModel sample.

The fix is simple.

Change this:

$filters = 'RecordingServer', 'Hardware', 'Camera' | ForEach-Object {
        [VideoOS.ConfigurationApi.ClientService.ItemFilter]::new($_, $null, 'Enabled')
}

To this:

$filters = 'RecordingServer', 'Hardware', 'Camera' | ForEach-Object {
        [VideoOS.ConfigurationApi.ClientService.ItemFilter]::new($_, @(), 'Enabled')
}

Put simply, change the $null to @().

This fix was tested against 2022 R3, 2025 R3, and 2026 R1.