Visual Studio Extension requires .NET Core 2.1 Runtime

[vxfield]

Describe the bug

When installing the Visual Studio Quantum Development Kit Extension, it shows a pre-requisite of:
.NET Core 2.1 Runtime (out of support)
but the extension and QDK tools actually depends on .NET Core 3.1.

The expected behavior is to show the following pre-requisite:
.NET Core 3.1 Runtime

Or if we move to .NET 6, the .NET 6 runtime.

To Reproduce

Steps to reproduce the behavior:

1. Have installation of VS 2019 that does not have .NET Core 2.1 SDK or runtime installed
2. Attempt to install the Visual Studio Quantum Development Kit Extension
3. See the pre-requisite of .NET Core 2.1 Runtime (out of support)

Expected behavior

The expected behavior is to show the following pre-requisite:
.NET Core 3.1 Runtime

Or if we move to .NET 6, the .NET 6 runtime.

System information

• Version of the NuGet package or extension for which the problem occurs
  • I found this issue testing the 0.21.2112.180657 beta version
• Your operating system and .NET Core version
  • I had a "clean" Windows 10 and Visual Studio 2019 installation with just .NET Core 3.1 runtime and SDK installed.

Potential fix

It looks like the pre-requisite comes from this line in the vsixmanifest.

<Prerequisite Id="Microsoft.Net.Core.Component.SDK.2.1" Version="[15.8.27924.0,)" DisplayName=".NET Core 2.1 development tools" />