Update microsoft-tunnel-prerequisites.md

We received a query asking if we support RHEL8.6. Our position is that we do not state support of any additional versions except the ones listed in the Supported Linux Distribution Table until we can prioritize and test support for a specific version.  

RHEL version support statement must clearly call out that we support only the versions stated in the Supported Linux Distributions table.

Author: OluchiC

memdocs/intune/protect/microsoft-tunnel-prerequisites.md

@@ -48,6 +48,9 @@ The following sections detail the prerequisites for the Microsoft Tunnel, and pr
 ## Linux server
 
 Set up a Linux based virtual machine or a physical server on which Microsoft Tunnel Gateway will install.
+ > [!NOTE]
+  > Please note we support the only OS and container versions listed in this table. We will update this list as we are able to prioritize, test, and verify support for newly available OS versions. 
+
 
 - **Supported Linux distributions** - The following table details which versions of Linux are supported for the Tunnel server, and the container they require: