aba4786d

By: Tom Sydney Kerckhove <syd@cs-syd.eu>

mutationCheck: drop the inline 'config' attrset, keep only 'configFile'

The 'config' attrset was an awkward halfway house: callers built a
Nix-shaped value that we then rendered to YAML via builtins.toJSON. With
'configFile', the YAML is the source of truth, hand-maintained in the
consuming repo as a sibling file. Move sydtest's own in-repo checks to
this style via ./nix/mutation.yaml.
forwardCompatibilitymutation-manifest-examplemutation-opt-env-confmutation-safe-coloured-textmutation-sydtest-mutation-examplepre-commitreleaseshellconfiguredevShelldefaultx86_64-linux