AuthenticodeCheck should warn/error on non-Windows

[ThomasNieto]

Prerequisites

• [X] Write a descriptive title.
• [X] Make sure you are able to repro it on the latest released version
• [X] Search the existing issues.

Steps to reproduce

If you use AuthenticodeCheck parameter on non-Windows it silently passes instead of writing a message to the user that signatures wasn't actually checked.

https://github.com/PowerShell/PSResourceGet/blob/949c26aed924aca64cc4d7a4d36271562eed5d01/src/code/Utils.cs#L2005-L2009

Expected behavior

Write warning/error that parameter isn't supported on non-Windows.

Actual behavior

Nothing

Error details

No response

Environment data

n/a

Visuals

No response

[SydneyhSmith]

A warning seems appropriate here