Remove now unnecessary package

Author: danielmarbach

src/Directory.Packages.props

@@ -72,7 +72,6 @@
     <PackageVersion Include="System.Configuration.ConfigurationManager" Version="8.0.1" />
     <PackageVersion Include="System.Diagnostics.PerformanceCounter" Version="8.0.1" />
     <PackageVersion Include="System.DirectoryServices.AccountManagement" Version="8.0.1" />
-    <PackageVersion Include="System.Linq.Async" Version="6.0.1" />
     <PackageVersion Include="System.Management" Version="8.0.0" />
     <PackageVersion Include="System.Management.Automation" Version="7.4.7" />
     <PackageVersion Include="System.Reactive.Linq" Version="6.0.1" />

src/ServiceControl.UnitTests/ServiceControl.UnitTests.csproj

@@ -20,7 +20,6 @@
     <PackageReference Include="NUnit3TestAdapter" />
     <PackageReference Include="Particular.Approvals" />
     <PackageReference Include="PublicApiGenerator" />
-    <PackageReference Include="System.Linq.Async" />
   </ItemGroup>
 
 </Project>