ConcurrencyLimitTest frequently fails on Windows machines

[jander-msft]

See https://runfo.azurewebsites.net/search/tests/?q=started%3A%7E7+definition%3Adotnet-monitor-ci+name%3AConcurrencyLimitTest

Typical failing callstack:
System.Threading.Tasks.TaskCanceledException : The operation was canceled.\r\n---- System.IO.IOException : Unable to read data from the transport connection: The I/O operation has been aborted because of either a thread exit or an application request..\r\n-------- System.Net.Sockets.SocketException : The I/O operation has been aborted because of either a thread exit or an application request.
at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) in System.Net.Http.dll:token 0x600048e+0x1685
at System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken) in System.Net.Http.dll:token 0x6000732+0x44d
at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) in System.Net.Http.dll:token 0x60007be+0x345
at Microsoft.Extensions.Http.Logging.LoggingHttpMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) in Microsoft.Extensions.Http.dll:token 0x60000b6+0x13f
at Microsoft.Extensions.Http.Logging.LoggingScopeHttpMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) in Microsoft.Extensions.Http.dll:token 0x60000bb+0x16f
at System.Net.Http.HttpClient.g__Core|83_0(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationTokenSource cts, Boolean disposeCts, CancellationTokenSource pendingRequestsCts, CancellationToken originalCancellationToken) in System.Net.Http.dll:token 0x6000275+0x216
at Microsoft.Diagnostics.Monitoring.UnitTests.HttpApi.ApiClient.SendAndLogAsync(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationToken token) in //src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/HttpApi/ApiClient.cs:line 428
at Microsoft.Diagnostics.Monitoring.UnitTests.HttpApi.ApiClient.EgressTraceAsync(Int32 processId, Int32 durationSeconds, String egressProvider, CancellationToken token) in //src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/HttpApi/ApiClient.cs:line 318
at Microsoft.Diagnostics.Monitoring.UnitTests.HttpApi.ApiClientExtensions.EgressTraceAsync(ApiClient client, Int32 processId, Int32 durationSeconds, String egressProvider) in //src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/HttpApi/ApiClientExtensions.cs:line 292
at Microsoft.Diagnostics.Monitoring.UnitTests.EgressTests.EgressTraceWithDelay(ApiClient apiClient, Int32 processId, Boolean delay) in //src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/EgressTests.cs:line 233
at Microsoft.Diagnostics.Monitoring.UnitTests.EgressTests.EgressTraceWithDelay(ApiClient apiClient, Int32 processId, Boolean delay) in //src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/EgressTests.cs:line 241
at Microsoft.Diagnostics.Monitoring.UnitTests.EgressTests.b__8_0(AppRunner appRunner, ApiClient apiClient) in //src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/EgressTests.cs:line 160
at Microsoft.Diagnostics.Monitoring.UnitTests.Runners.ScenarioRunner.<>c__DisplayClass0_0.<b__0>d.MoveNext() in //src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/Runners/ScenarioRunner.cs:line 54
--- End of stack trace from previous location ---
at Microsoft.Diagnostics.Monitoring.UnitTests.Runners.AppRunnerExtensions.ExecuteAsync(AppRunner runner, Func1 func) in /_/src/Tests/Microsoft.Diagnostics.Monitoring.TestCommon/Runners/AppRunnerExtensions.cs:line 46 at Microsoft.Diagnostics.Monitoring.UnitTests.Runners.AppRunnerExtensions.ExecuteAsync(AppRunner runner, Func1 func) in //src/Tests/Microsoft.Diagnostics.Monitoring.TestCommon/Runners/AppRunnerExtensions.cs:line 46
at Microsoft.Diagnostics.Monitoring.UnitTests.Runners.AppRunnerExtensions.ExecuteAsync(AppRunner runner, Func1 func) in /_/src/Tests/Microsoft.Diagnostics.Monitoring.TestCommon/Runners/AppRunnerExtensions.cs:line 46 at Microsoft.Diagnostics.Monitoring.UnitTests.Runners.ScenarioRunner.SingleTarget(ITestOutputHelper outputHelper, IHttpClientFactory httpClientFactory, DiagnosticPortConnectionMode mode, String scenarioName, Func3 appValidate, Func3 postAppValidate, Action1 configureApp, Action`1 configureTool) in /_/src/Tests/Micros