I haven't ran into this error nor do I run a BYOL but it seems like NTP is installed on your instance and/or the matillion package can't figure out which package to use for ntp on your flavor of Linux. Have you tried installing ntp manually just to resolve the dependency on ntp before the update?
@Bryan - thanks for the response! I did go ahead and try to install ntp manually, and discovered that (surprise!) ntp has been completely deprecated for RHEL 8.x and replaced with chrony. I think I will proceed by skipping this dependency. If anyone else has encountered this issue, please chime in. RHEL 7.x is so close to EOL that many highly regulated organizations would be forbidden from using it.