cuda-modules: fix sort predicate stability

Incorrect sorting predicate was found as part of
NixOS/nix#12106 where `nix` was crashing on
the code like:

    $ nix eval --expr 'builtins.sort (a: b: true) [ 1 2 3 ]'
    ...
    Aborted (core dumped)

Note: the crash happens here because sorting predicate does not
implement `isLess` and triggers assertion failures for
`std::stable_sort` that backs `builtins.sort`.

THe change restore `isLess` semantic for `preferable`.

Author: trofi

pkgs/development/cuda-modules/generic-builders/multiplex.nix

@@ -81,7 +81,7 @@ let
   redistArch = flags.getRedistArch hostPlatform.system;
 
   preferable =
-    p1: p2: (isSupported p2 -> isSupported p1) && (strings.versionAtLeast p1.version p2.version);
+    p1: p2: (isSupported p2 -> isSupported p1) && (strings.versionOlder p2.version p1.version);
 
   # All the supported packages we can build for our platform.
   # perSystemReleases :: List Package