Fixes divergence between the two test scripts.
The test doesn't need to be executed by default. It is just a
demonstration on how to use a custom scope that can be created with
the function `mkAuthentikScope`, that is available through the `lib`
flake output.
* provides a new function `lib.mkAuthentikScope` as a flake output to
create a custom scope with overrides outside of this flake
* adds a slightly altered version of existing vm test to demonstrate the
usage of `mkAuthentikScope` for overriding individual authentik
components in tests/override-scope.nix