Add deprecation warning to Uri.UserEscaped property documentation

Co-authored-by: gewarren <[email protected]>

Author: Copilot

xml/System/Uri.xml

@@ -6030,7 +6030,11 @@ The following examples show a URI and the results of calling <xref:System.Uri.Ge
           <format type="text/markdown"><![CDATA[
 
 ## Remarks
- The <xref:System.Uri.UserEscaped%2A> property is set to `true` to indicate that the string used to create the <xref:System.Uri> instance was completely escaped before it was passed to the constructor; that is, the `dontEscape` parameter of the constructor call was set to `true`.
+
+> [!CAUTION]
+> The <xref:System.Uri.UserEscaped%2A> property represents deprecated functionality that will not work as expected. The `dontEscape` parameter referenced by this property has been deprecated since .NET Framework 4 and will always be `false`. As a result, this property will always return `false` and should not be used to determine URI escaping behavior.
+
+ The <xref:System.Uri.UserEscaped%2A> property was originally designed to indicate that the string used to create the <xref:System.Uri> instance was completely escaped before it was passed to the constructor; that is, the `dontEscape` parameter of the constructor call was set to `true`. However, since the `dontEscape` parameter is now obsolete and always treated as `false`, this property will always return `false`.
 
 ## Examples
  The following example creates a <xref:System.Uri> instance and determines whether it was fully escaped when it was created.