Fix clienthellotest with TLSv1.3

If TLSv1.3 is enabled and combined with other options that extend the
size of the ClientHello, then the clienthello test can sometimes fail
because the ClientHello has grown too large. Part of the purpose of the
test is to check that the padding extension works properly. This requires
the ClientHello size to be kept within certain bounds.

By restricting the number of ciphersuites sent we can reduce the size of
the ClientHello.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5266)