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

quickshell/Services/niri-wpblur.kdl

@@ -1,4 +1,4 @@
 layer-rule {
     match namespace="dms:blurwallpaper"
     place-within-backdrop true
-}
+}