Remove unused ParamTypes method from DispatchProxyGenerator (#51119)

src/libraries/System.Reflection.DispatchProxy/src/System/Reflection/DispatchProxyGenerator.cs

@@ -427,7 +427,7 @@ private MethodBuilder AddMethodImpl(MethodInfo mi, int methodInfoIndex)
 
                 // object[] args = new object[paramCount];
                 il.Emit(OpCodes.Nop);
-                GenericArray<object> argsArr = new GenericArray<object>(il, ParamTypes(parameters, true).Length);
+                GenericArray<object> argsArr = new GenericArray<object>(il, parameters.Length);
 
                 for (int i = 0; i < parameters.Length; i++)
                 {
@@ -512,18 +512,6 @@ private MethodBuilder AddMethodImpl(MethodInfo mi, int methodInfoIndex)
                 return mdb;
             }
 
-            private static Type[] ParamTypes(ParameterInfo[] parms, bool noByRef)
-            {
-                Type[] types = new Type[parms.Length];
-                for (int i = 0; i < parms.Length; i++)
-                {
-                    types[i] = parms[i].ParameterType;
-                    if (noByRef && types[i].IsByRef)
-                        types[i] = types[i].GetElementType()!;
-                }
-                return types;
-            }
-
             // TypeCode does not exist in ProjectK or ProjectN.
             // This lookup method was copied from PortableLibraryThunks\Internal\PortableLibraryThunks\System\TypeThunks.cs
             // but returns the integer value equivalent to its TypeCode enum.