Update dependency NUnit to 4.5.1 (#819)

Co-authored-by: dependencyupdates[bot] <218638057+dependencyupdates[bot]@users.noreply.github.com>

Author: dependencyupdates[bot]

src/NServiceBus.Testing.Tests/NServiceBus.Testing.Tests.csproj

@@ -11,7 +11,7 @@
   <ItemGroup>
     <PackageReference Include="GitHubActionsTestLogger" Version="3.0.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
-    <PackageReference Include="NUnit" Version="4.5.0" />
+    <PackageReference Include="NUnit" Version="4.5.1" />
     <PackageReference Include="NUnit.Analyzers" Version="4.11.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="6.1.0" />
     <PackageReference Include="Particular.Approvals" Version="2.0.1" />