Add deprecation for PowerShell 3/4 to Profile psm1

[maddieclayton]

Description

#5149

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[markcowl]

We need to save a file in their user directory to indicate that we have displayed this message, simila to the pattern we use for enabling/disabling data collection

[maddieclayton]

@markcowl is this what you had in mind?

[markcowl]

This is exactly what I had in mind, but we want to make sure that any error in writing the file isn't bubbled up to the user. The safest thing would be to wrap the file write in a try/catch

[markcowl]

Also, use join-path, this will make this work across platforms

[markcowl]

on demand run here:https://azuresdkci.westus2.cloudapp.azure.com/view/PowerShell/job/powershell-demand/432/

signing run here: https://azuresdkci.westus2.cloudapp.azure.com/view/PowerShell/job/ps-sign/115/

[maddieclayton]

Updated sign job here: https://azuresdkci.westus2.cloudapp.azure.com/view/PowerShell/job/ps-sign/118/
on demand job here: https://azuresdkci.westus2.cloudapp.azure.com/view/PowerShell/job/powershell-demand/437/