Looks like this has never been in the core package: https://packages.debian.org/search?searchon=contents&keywords=resolveip&mode=path&suite=unstable&arch=any /usr/bin/resolveipmariadb-server-10.0 [arm64], mariadb-server-10.1 [powerpc], mariadb-server-10.3 [ei ia64, powerpc, s390, sparc], mariadb-server-5.5 [sparc, arm64], mysql-server-5.5 [sparc, ia64, s390, arm64], mysql-server-5.7 [ei hurd-i386, ia64, kfreebsd-i386, s390, sparc, sparc64], percona-xtradb-cluster-server-5.5 [sparc, arm64]
Moving the file requires some consideration for backwards compatibility etc. Would you like to take a look at this and try to come up with a solution? See https://wiki.debian.org/Teams/MySQL/patches on how to use Salsa-CI to test and submit patches.