Bump Microsoft.Bcl.AsyncInterfaces from 1.1.1 to 5.0.0 in /Ix.NET/Source

Bumps [Microsoft.Bcl.AsyncInterfaces](https://github.com/dotnet/runtime) from 1.1.1 to 5.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](https://github.com/dotnet/runtime/commits)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Ix.NET/Source/System.Linq.Async/System.Linq.Async.csproj

@@ -26,7 +26,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Condition="'$(TargetFramework)' != 'netcoreapp3.1' and '$(TargetFramework)' != 'netstandard2.1' " Include="Microsoft.Bcl.AsyncInterfaces" Version="1.1.1" />
+    <PackageReference Condition="'$(TargetFramework)' != 'netcoreapp3.1' and '$(TargetFramework)' != 'netstandard2.1' " Include="Microsoft.Bcl.AsyncInterfaces" Version="5.0.0" />
     <ReferenceAssemblyProjectReference Include="..\refs\System.Linq.Async.Ref\System.Linq.Async.Ref.csproj" />
   </ItemGroup>
 

Ix.NET/Source/refs/System.Linq.Async.Ref/System.Linq.Async.Ref.csproj

@@ -10,7 +10,7 @@
 
   <ItemGroup>
     <PackageReference Condition="'$(TargetFramework)' != 'netcoreapp3.1' and '$(TargetFramework)' != 'netstandard2.1' " 
-                      Include="Microsoft.Bcl.AsyncInterfaces" Version="1.1.1" />
+                      Include="Microsoft.Bcl.AsyncInterfaces" Version="5.0.0" />
   </ItemGroup>
 
   <ItemGroup>