Try to catch memory dump for instrumentation telemetry tests (#6675)

## Summary of changes

Try to grab a memory dump if `dotnet build` fails as part of the
instrumentation tests

## Reason for change

Since updating to 9.0.102, we've seen cases of the `dotnet build`
hanging on arm64. In this test we explicitly build a "forwarder" app,
and that has a hung several times in CI now.

## Implementation details

Use the memory dump helper to try to grab a dump. We've only seen this
happen on linux arm64 so far, so haven't bothered to hook up the Windows
monitoring or anything like that

## Test coverage

If the tests pass, that's good enough for me until we see this flake
manifest again.

tracer/test/Datadog.Trace.ClrProfiler.IntegrationTests/InstrumentationTests.cs

@@ -606,7 +606,14 @@ public string GetAppPath(ITestOutputHelper output, EnvironmentHelper environment
                     RedirectStandardError = true,
                 };
                 using var process = new ProcessHelper(Process.Start(startInfo), x => output.WriteLine(x), x => output.WriteLine(x));
-                process.Process.WaitForExit(30_000);
+                const int timeoutMs = 30_000;
+                if (!process.Process.WaitForExit(timeoutMs))
+                {
+                    var tookMemoryDump = MemoryDumpHelper.CaptureMemoryDump(process.Process, includeChildProcesses: true);
+                    process.Process.Kill();
+                    throw new Exception($"The sample did not exit in {timeoutMs}ms. Memory dump taken: {tookMemoryDump}. Killing process.");
+                }
+
                 process.Drain(15_000);
 
                 var extension = EnvironmentTools.IsWindows() ? ".exe" : string.Empty;