[release/8.x] Bump Microsoft.Diagnostics.DbgShim (#8107)

Bumps [Microsoft.Diagnostics.DbgShim](https://github.com/dotnet/diagnostics) from 9.0.553101 to 9.0.621003.
- [Release notes](https://github.com/dotnet/diagnostics/releases)
- [Commits](dotnet/diagnostics@v9.0.553101...v9.0.621003)

---
updated-dependencies:
- dependency-name: Microsoft.Diagnostics.DbgShim
  dependency-version: 9.0.621003
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

eng/dependabot/nuget.org/Versions.props

@@ -2,6 +2,6 @@
   <!-- Import references updated by Dependabot. -->
   <PropertyGroup>
     <!-- dotnet/diagnostics references -->
-    <MicrosoftDiagnosticsMonitoringShippedVersion>9.0.553101</MicrosoftDiagnosticsMonitoringShippedVersion>
+    <MicrosoftDiagnosticsMonitoringShippedVersion>9.0.621003</MicrosoftDiagnosticsMonitoringShippedVersion>
   </PropertyGroup>
 </Project>

src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTestCommon/EndpointInfoSourceCallback.cs

@@ -8,10 +8,8 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Reflection;
 using System.Threading;
 using System.Threading.Tasks;
-using Xunit;
 using Xunit.Abstractions;
 
 namespace Microsoft.Diagnostics.Monitoring.TestCommon
@@ -80,7 +78,9 @@ public virtual async Task OnBeforeResumeAsync(IEndpointInfo endpointInfo, Cancel
         {
             if (endpointInfo.RuntimeVersion.Major >= 8 && !string.IsNullOrEmpty(_startupHookPath))
             {
-                await ApplyStartupHookAsync(new DiagnosticsClient(endpointInfo.ProcessId), _startupHookPath, token);
+                DiagnosticsClient client = new(endpointInfo.ProcessId);
+
+                await client.ApplyStartupHookAsync(_startupHookPath, token);
             }
         }
 
@@ -106,19 +106,6 @@ public Task OnRemovedEndpointInfoAsync(IEndpointInfo info, CancellationToken tok
                 token);
         }
 
-        private static Task ApplyStartupHookAsync(DiagnosticsClient client, string path, CancellationToken token)
-        {
-            // DiagnosticsClient.ApplyStartupHookAsync currently is not public
-            MethodBase applyStartupHookAsync =
-                typeof(DiagnosticsClient).GetMethod(
-                    "ApplyStartupHookAsync",
-                    BindingFlags.Instance | BindingFlags.NonPublic);
-
-            Assert.NotNull(applyStartupHookAsync);
-
-            return (Task)applyStartupHookAsync.Invoke(client, new object[] { path, token });
-        }
-
         private static async Task<IEndpointInfo> WaitForCompletionAsync(string operation, SemaphoreSlim semaphore, List<CompletionEntry> entries, ITestOutputHelper outputHelper, AppRunner runner, TimeSpan timeout)
         {
             CompletionEntry entry = new(runner);