fix: use function from lib instead of builtins

Author: mrjones2014

nix/shell-plugins.nix

@@ -29,8 +29,7 @@ in {
       # depending on if it's using `home-manager` or not; this means that Nix can still
       # compute the dependency tree, even though we're discarding string context here,
       # since the packages are still referred to below without discarding string context.
-      builtins.unsafeDiscardStringContext (baseNameOf (getExe package)))
-      cfg.plugins;
+      strings.unsafeDiscardStringContext (baseNameOf (getExe package))) cfg.plugins;
     # Explanation:
     # Map over `cfg.plugins` (the value of the `plugins` option provided by the user)
     # and for each package specified, get the executable name, then create a shell alias