Test Runner displays "Workload Updates are available"

[TheAngryByrd]

Describe the bug

This typically comes from CLI output when someone has dotnet workloads that need updated.

@baronfel said there's some env vars we can use to stop that output. Or maybe we need to find a better way of getting the output of discovering tests.

Steps to reproduce

Link to sample reproduction

Expected behaviour

Screenshots

Machine info

• OS: Windows/Mac/Linux
• .NET SDK version: [e.g. 5.0.100]
• Ionide version: [e.g 5.0.1, don't use descriptions like latest ]

Additional context

Add any other context about the problem here.