Update message for generic type. (#36434)

Author: AaronRobinsonMSFT

src/libraries/System.Private.CoreLib/src/Resources/Strings.resx

@@ -1343,7 +1343,7 @@
     <value>The specified object must not be an instance of a generic type.</value>
   </data>
   <data name="Argument_NeedNonGenericType" xml:space="preserve">
-    <value>The specified Type must not be a generic type definition.</value>
+    <value>The specified Type must not be a generic type.</value>
   </data>
   <data name="Argument_NeedStructWithNoRefs" xml:space="preserve">
     <value>The specified Type must be a struct containing no references.</value>