Restore ServicePointManager SSL callback bridge for .NET 10 (#1275)

Replace #if !NET10_0_OR_GREATER guards with #pragma warning disable SYSLIB0014
so that ServicePointManager.ServerCertificateValidationCallback is read and
applied to SocketsHttpHandler.SslOptions in all target frameworks, including
.NET 10. Without this bridge, apps relying on that callback to handle
self-signed or name-mismatched certificates would fail SSL handshake after
migrating to .NET 10.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: claudiamurialdo

dotnet/src/dotnetframework/GxClasses/Domain/GxHttpClient.cs

@@ -207,11 +207,9 @@ private static HttpClient GetHttpClientInstance(Uri URI, int timeout, ArrayList
 
 		private static string HttpClientInstanceIdentifier(string proxyHost, int proxyPort, List<string> fileCertificateCollection, int timeout)
 		{
-#if !NET10_0_OR_GREATER
+#pragma warning disable SYSLIB0014
 			bool defaultSslOptions = ServicePointManager.ServerCertificateValidationCallback == null;
-#else
-			bool defaultSslOptions = true;
-#endif
+#pragma warning restore SYSLIB0014
 			if (string.IsNullOrEmpty(proxyHost) && CollectionUtils.IsNullOrEmpty(fileCertificateCollection) && timeout== DEFAULT_TIMEOUT && defaultSslOptions)
 			{
 				return string.Empty;
@@ -281,15 +279,15 @@ private static SocketsHttpHandler GetHandler(Uri URI, ArrayList authCollection,
 
 		private static void SetSslOptions(SocketsHttpHandler handler)
 		{
-#if !NET10_0_OR_GREATER
+#pragma warning disable SYSLIB0014
 			if (ServicePointManager.ServerCertificateValidationCallback != null)
 			{
 				handler.SslOptions = new SslClientAuthenticationOptions
 				{
 					RemoteCertificateValidationCallback = ServicePointManager.ServerCertificateValidationCallback
 				};
 			}
-#endif
+#pragma warning restore SYSLIB0014
 		}
 #else
 		[SecuritySafeCritical]

dotnet/src/dotnetframework/GxMail/Exchange/CertificateCallback.cs

@@ -5,12 +5,12 @@ namespace GeneXus.Mail.Exchange
 {
     public static class CertificateCallback
     {
-#if !NET10_0_OR_GREATER
+#pragma warning disable SYSLIB0014
 		static CertificateCallback()
         {
             ServicePointManager.ServerCertificateValidationCallback = CertificateValidationCallBack;
         }
-#endif
+#pragma warning restore SYSLIB0014
 
 		public static void Initialize()
         {