Remove EVP_MD_meth* again

Remove EVP_MD_meth* again

Erlang upstream disabled the otp_test_engine for LibreSSL >= 3.5 without
explanation. It was the only reason we added this garbage API in the first
place. Meanwhile libfido2 started using it for a mock up of OpenSSL 3's
broken fetch design with old API. This is pointless, so all this garbage
goes away again (in particular we can remove the absolutely horrifying
EVP_MD_meth_set_app_datasize() again).

ok jsing