Use dotnet exec to run test app in CheckTargetFrameworkDisplayName (#45332)

"dotnet run" does some additional steps like restore and build that we don't need and it can cause issues with additional characters in stdout like in #45042 (comment)

Switch to executing the built .dll directly.

Author: akoeplinger

test/Microsoft.NET.Build.Tests/GivenThatWeWantToControlGeneratedAssemblyInfo.cs

@@ -855,11 +855,11 @@ static void Main(string[] args)
                 .Should()
                 .Pass();
 
-            var result = new DotnetCommand(Log, "run")
-                .WithWorkingDirectory(Path.Combine(testAsset.Path, testProject.Name))
-                .Execute();
+            var exePath = Path.Combine(buildCommand.GetOutputDirectory(testProject.TargetFrameworks).FullName, testProject.Name + ".dll");
+
+            var result = new DotnetCommand(Log, "exec", exePath).Execute();
             result.Should().Pass();
-            result.StdOut.StripTerminalLoggerProgressIndicators().Should().BeEquivalentTo(expectedFrameworkDisplayName);
+            result.StdOut.Should().BeEquivalentTo(expectedFrameworkDisplayName);
         }
     }
 }