Clean dead code for System.Console (#28908)

* Clean dead code for System.Console

* Undo bad changes

Author: MisinformedDNA

src/Common/src/System/Text/OSEncoder.cs

@@ -240,13 +240,5 @@ public override unsafe void Convert(char* chars, int charCount,
             charsUsed = 0;
             completed = false;
         }
-
-        public Encoding Encoding
-        {
-            get
-            {
-                return _encoding;
-            }
-        }
     }
 }