Provide a clearer error if a .NET Task assembly uses a .NET Runtime that is unsupported by the .NET Runtime of the .NET TaskHost Node

[baronfel]

Summary

When loading .NET Tasks on an out of proc .NET TaskHost Node, we locate the MSbuild from the current SDK and have that Node load and execute a Task in the assembly. If there is a runtime mismatch between that host node and the Task dll, the user will see a loading error - we should make sure that this error is very clear - the load error comes because the Task author tried to load the dll on a runtime that the Task user didn't have.

Background and Motivation

See above

Proposed Feature

When launching the taskhost node, we should be able to

• know what the SDK version (and therefore the .NET Runtime the MSBuild binary would use) of the TaskHost is
• probe the assembly to be loaded to find its Runtime version (based on assembly attributes and/or runtimeconfig.json parsing)
• error if the discovered runtime version isn't supported by the runtime of the SDK

Alternative Designs

No response