Most of our visitors have custom destructors because they wrap C types,
and need to manually call destructors for those types. Because of this,
the implicitly generated copy constructors and copy-assignment operators
are not safe due copying pointers rather than data. Since we don't need
these features just delete them, so any attempt to use them would be a
compilation error. This doesn't fix any existing issue except stopping
coverity from complaining, but it does prevent new issues in the future.
Acked-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29662>