Starting with the .NET Framework 4.6, this type implements the IDisposable interface. ... For apps that target the .NET Framework 4.5.2 and earlier versions, the X509Certificate class does not implement the IDisposable interface and therefore does not have a Dispose method.
Could start disposing it in builds that support net46 and/or netstandard2.0.
This commit doesn't ensure that an ObjectDisposedException will be thrown
if an object is used after it's disposed; a NullReferenceException or
some other exception may be thrown instead. These are internal types
that should always be used correctly in this code, so tracking incorrect
use of Dispose is a low priority.