Fix Stack<T> type reference (#8566)

Author: Kissaki

xml/System.Collections.Generic/Stack`1.xml

@@ -97,7 +97,7 @@
   
  Three main operations can be performed on a <xref:System.Collections.Generic.Stack%601?displayProperty=nameWithType> and its elements:  
   
--   <xref:System.Collections.Generic.Stack%601.Push%2A> inserts an element at the top of the <xref:System.Collections.Stack>.  
+-   <xref:System.Collections.Generic.Stack%601.Push%2A> inserts an element at the top of the <xref:System.Collections.Generic.Stack%601>.  
   
 -   <xref:System.Collections.Generic.Stack%601.Pop%2A> removes an element from the top of the <xref:System.Collections.Generic.Stack%601>.