Update nixica to 0.9.0

gitlab-ci is currently on nixica 0.3.0. Update to 0.9.0 which includes:

• Named-arg mkFlake (mkFlake { inherit inputs; modules = ./nix; })
• dev/ → ci/ partition rename
• importAndPublish pattern
• CI module options (omnix, cachix, discover)

This also means the flake.nix call site needs updating from:

outputs = inputs: inputs.nixica.lib.mkFlake inputs ./nix;

to:

outputs = inputs: inputs.nixica.lib.mkFlake { inherit inputs; modules = ./nix; };

@smartypants