nixosTests.zrepl: migrate to runTest

Part Of #386873

nixos/tests/all-tests.nix

···
   zoneminder = handleTest ./zoneminder.nix {};
   zookeeper = handleTest ./zookeeper.nix {};
   zram-generator = handleTest ./zram-generator.nix {};
-  zrepl = handleTest ./zrepl.nix {};
+  zrepl = runTest ./zrepl.nix;
   zsh-history = runTest ./zsh-history.nix;
   zwave-js = runTest ./zwave-js.nix;
   zwave-js-ui = runTest ./zwave-js-ui.nix;

nixos/tests/zrepl.nix

···
-import ./make-test-python.nix ({
+{
   name = "zrepl";
 
   nodes.host =
-    { config, pkgs, ... }:
+    { pkgs, ... }:
     {
       config = {
         # Prerequisites for ZFS and tests.
···
             "zrepl_zfs_snapshot_duration_count{filesystem=\"test\"}" in out
         ), "zrepl snapshot counter for test was not found in Prometheus output"
   '';
-})
+}