tree-wide: format with nixfmt

Another saturday another useless formatter change.
It's my dotfiles, after all

alejandra doesn't handle c-style inline comments well.

nix/packages/by-name/nix-which/package.nix

@@ -2,26 +2,27 @@
   writeShellApplication,
   which,
   lib,
-}: let
+}:
+let
   # Use this to not pollute the PATH inside
   # Otherwise nix-which which will be an edge case
   whichExe = "${lib.getExe which}";
 in
-  writeShellApplication {
-    name = "nix-which";
-    text = ''
-      if [ "$#" -ne 1 ]; then
-          echo "Must provide exactly one argument, the package to be dereferenced"
-          exit 1
-      fi
-      target="$1"
+writeShellApplication {
+  name = "nix-which";
+  text = ''
+    if [ "$#" -ne 1 ]; then
+        echo "Must provide exactly one argument, the package to be dereferenced"
+        exit 1
+    fi
+    target="$1"
 
-      target="$(${whichExe} "$target")"
-      echo "==> $target"
+    target="$(${whichExe} "$target")"
+    echo "==> $target"
 
-      while [ -L "$target" ]; do
-          target="$(readlink "$target")"
-          echo "==> $target"
-      done
-    '';
-  }
+    while [ -L "$target" ]; do
+        target="$(readlink "$target")"
+        echo "==> $target"
+    done
+  '';
+}