The <openssl/hmac.h> header was unused and including the
header might cause build failure when OpenSSL doesn't have
Engines support enabled.
See https://fedoraproject.org/wiki/Changes/OpensslDeprecateEngine
Removes unused hmac includes after Remove OpenSSL Engine support
(commit
ef7aba70) removed engine support.
Merge branch 'main-openssl-engine' into 'main'
See merge request isc-projects/bind9!9228