make dicts in NamedPipeBase strong typed (#49984)

Author: Youssef1313

src/Cli/dotnet/Commands/Test/IPC/NamedPipeBase.cs

@@ -14,8 +14,8 @@ namespace Microsoft.DotNet.Cli.Commands.Test.IPC;
 
 internal abstract class NamedPipeBase
 {
-    private readonly Dictionary<Type, object> _typeSerializer = [];
-    private readonly Dictionary<int, object> _idSerializer = [];
+    private readonly Dictionary<Type, INamedPipeSerializer> _typeSerializer = [];
+    private readonly Dictionary<int, INamedPipeSerializer> _idSerializer = [];
 
     public void RegisterSerializer(INamedPipeSerializer namedPipeSerializer, Type type)
     {
@@ -25,9 +25,9 @@ public void RegisterSerializer(INamedPipeSerializer namedPipeSerializer, Type ty
 
     protected INamedPipeSerializer GetSerializer(int id, bool skipUnknownMessages = false)
     {
-        if (_idSerializer.TryGetValue(id, out object serializer))
+        if (_idSerializer.TryGetValue(id, out INamedPipeSerializer serializer))
         {
-            return (INamedPipeSerializer)serializer;
+            return serializer;
         }
         else
         {
@@ -46,8 +46,8 @@ protected INamedPipeSerializer GetSerializer(int id, bool skipUnknownMessages =
 
 
     protected INamedPipeSerializer GetSerializer(Type type)
-        => _typeSerializer.TryGetValue(type, out object serializer)
-            ? (INamedPipeSerializer)serializer
+        => _typeSerializer.TryGetValue(type, out INamedPipeSerializer serializer)
+            ? serializer
             : throw new ArgumentException(string.Format(
                 CultureInfo.InvariantCulture,
 #if dotnet