Update Go toolchain to 1.22.4, which addresses two vulnerabilities in the Go
stdlib.
* CVE-2024-24789: impacts handling of certain types of invalid zip files, which
could be exploited to create a zip file with unexpected contents. This could
potentially impact Nomad users of `artifact` blocks who download untrusted
artifacts.
* CVE-2024-24790: impacts parsing of IPv4-mapped IPv6 addresses.