[BuildCheck Suggestion]: Detect use of Exec task to run "dotnet build" or similar commands

[dsplaisted]

Summary

We should warn when an Exec task is used to spawn a new build via dotnet build, dotnet publish, etc.

Background and Motivation

It's usually a bad pattern to run dotnet build, dotnet publish, etc from an Exec task, since this spawns an entirely separate build that the MSBuild engine doesn't have visibility over. We should recommend using an MSBuild task instead.

Sample issue or antipattern that the check should be flagging

  <Target Name="BuildVer2022">
    <Exec Command="dotnet build -p:C3DVersion=Ver2022 -c $(Configuration)"/>
  </Target>

Source: dotnet/sdk#45034 (comment)

Sample output

No response