Refactor pre-commit hooks to use prek (#976)

* ci: change to prek for pre-commit

* refactor: fix shellcheck warnings for the scripts

* chore: unify whitespace formatting

* nix: add prek to dev shell

core/internal/config/embedded/niri-binds.kdl

@@ -192,4 +192,4 @@ binds {
     // === System Controls ===
     Mod+Escape allow-inhibiting=false { toggle-keyboard-shortcuts-inhibit; }
     Mod+Shift+P { power-off-monitors; }
-}
+}