Guarded CI module, bump gitlab-ci to 0.20.2
Summary
- Move CI config from
dev/nix/modules/flake/ci.nixtodev/nix/ci.nix(config, not a guarded flake-parts module path) - Make it a guarded module with
nixica.ci.enable(default true) andnixica.ci.auto-discover.enable(default false) - Root flake enables auto-discover via
nixica-dev.nix; test flakes get CI without auto-discover - Bump gitlab-ci from 0.19.0 to 0.20.2
Closes #13 (closed), #14 (closed)