Fix incorrect UriBuilder.Scheme property documentation about valid schemes (#11648)

Author: Copilot

xml/System/UriBuilder.xml

@@ -1139,17 +1139,8 @@ The following example sets the <xref:System.UriBuilder.Query> property.
           <format type="text/markdown"><![CDATA[
 
 ## Remarks
- The following table lists the valid scheme names for the <xref:System.UriBuilder.Scheme> property.
-
-|Scheme|Description|
-|------------|-----------------|
-|file|The resource is a file on the local computer.|
-|ftp|The resource is accessed through FTP.|
-|gopher|The resource is accessed through the Gopher protocol.|
-|http|The resource is accessed through HTTP.|
-|https|The resource is accessed through SSL-encrypted HTTP.|
-|mailto|The resource is an email address and is accessed through SMTP.|
-|news|The resource is accessed through NNTP.|
+
+The set accessor validates the scheme name for validity according to RFC 2396. The scheme name must begin with a letter and must contain only letters, digits, and the characters ".", "+", or "-".
 
  ]]></format>
         </remarks>