- we previously used `@stdlib/utils` instead of the child package
`@stdlib/copy`, which is a lot smaller and contains our only use of
the parent
- this saves 140+MB of dependencies
- we keep ending up with multiple versions of the depedency in our tree,
and it's causing problems when comparing instances
- the workaround I'm implementing for now is to bump the package
everywhere and set a resolution so we only have 1 shared instance
- hopefully we can come up with a better method down the line
- there's a weird situation when we have mixed versions of the
dependency because different libraries try to compare instances
- this brings the usage up to 1.2.21 so we can fix the build for now
no issue
- The way we're going to implement milestones diverged from the original idea of handling email sending within the milestone-emails package, as we'll be sending events instead and will utilise the StaffService to listen to them and send the emails
- This renames the package as well as the service in core itself and all relevant tests
