Unable to generate spec (bitrot in schematyper dependency)

Bug

The generate script depends on https://github.com/idubinskiy/schematyper, but this dependency is unmaintained and uninstallable since 2023.

There's an upstream pull request that should fix this, but it's just sitting there:
https://github.com/idubinskiy/schematyper/pull/22

If this has been already solved (for instance by forking), then the docs need to be updated.

Expected Behavior

go get should install the dependency.

Actual Behavior

$ go get -u github.com/idubinskiy/schematyper
go: gopkg.in/alecthomas/kingpin.v2@v2.4.0: parsing go.mod:
	module declares its path as: github.com/alecthomas/kingpin/v2
	        but was required as: gopkg.in/alecthomas/kingpin.v2
	trying gopkg.in/alecthomas/kingpin.v2@v2.3.2
go: gopkg.in/alecthomas/kingpin.v2@v2.3.2: parsing go.mod:
	module declares its path as: github.com/alecthomas/kingpin/v2
	        but was required as: gopkg.in/alecthomas/kingpin.v2
	trying gopkg.in/alecthomas/kingpin.v2@v2.3.1
go: gopkg.in/alecthomas/kingpin.v2@v2.3.1: parsing go.mod:
	module declares its path as: github.com/alecthomas/kingpin/v2
	        but was required as: gopkg.in/alecthomas/kingpin.v2
	trying gopkg.in/alecthomas/kingpin.v2@v2.3.0
go: gopkg.in/alecthomas/kingpin.v2@v2.3.0: go.mod has non-....v2 module path "github.com/alecthomas/kingpin" at revision v2.3.0
	restoring gopkg.in/alecthomas/kingpin.v2@v2.2.6

Reproduction Steps

1. uninstall schematyper if already present, clear package cache
2. go get -u github.com/idubinskiy/schematyper

Start with the generate script and reproduce the go get -u github.com/idubinskiy/schematyper failure after clearing the package cache. Check whether the upstream schematyper pull request or another maintained source resolves installation; done means the dependency can be installed, or the documentation accurately points to the working solution.