fix: reinstate System.Linq.AsyncEnumerable for integration tests

Author: jskeet

Directory.Packages.props

@@ -24,6 +24,7 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.14.0" />
     <PackageVersion Include="Microsoft.Extensions.Logging.Abstractions" Version="9.0.11" />
     <PackageVersion Include="System.Collections.Immutable" Version="9.0.11" />
+    <PackageVersion Include="System.Linq.AsyncEnumerable" Version="10.0.0" />
 
     <!-- Other third party packages -->
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.4" />

Google.Api.Generator.IntegrationTests/Google.Api.Generator.IntegrationTests.csproj

@@ -12,6 +12,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
+	<PackageReference Include="System.Linq.AsyncEnumerable" />
   </ItemGroup>
 
   <ItemGroup>