The (now-unofficial) Mac installation mechanism is the MacPorts system. MacPorts is a software package similar to the BSD ports facility that uses descriptors called Portfiles to download and install open source packages, either from pre-built cached binaries or from source.
Shibboleth and its dependencies have a set of official Portfiles that enable a fairly simple installation or upgrade of the entire stack on macOS. However, they don't always work because macOS changes frequently these days and the toolchain used is difficult to debug.
Of course, building Shibboleth from source is also possible (and tends to be more reliable but is much more work).
Upgrading to new releases is handled automatically when the port is used, or in the case of a source build when "make install" is run using the same installation prefix. The system prevents configuration files from being overwritten and skips "initial install" tasks like generating keys. Restart of the relevant services has to be done manually.