Update F# version used by the container

Author: ashmind

source/Container/Container.csproj

@@ -8,7 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="FSharp.Core" Version="6.0.1" />
+    <PackageReference Include="FSharp.Core" Version="8.0.300" />
     <PackageReference Include="Microsoft.Diagnostics.Runtime" Version="3.1.512801" />
     <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.10.13" />
     <PackageReference Include="protobuf-net" Version="3.0.101" />