tests/minio: fix broken minio test

Since last update minio pre allocates 2GiB of memory, so the test VM
needs more than that to not run out of memory.

We also remove the time based tests as it makes the test non deterministic

nixos/tests/minio.nix

@@ -43,17 +43,17 @@ import ./make-test-python.nix ({ pkgs, ... }:
 
         # Minio requires at least 1GiB of free disk space to run.
         virtualisation.diskSize = 4 * 1024;
+
+        # Minio pre allocates 2GiB or memory, reserve some more
+        virtualisation.memorySize = 4096;
       };
     };
 
     testScript = ''
-      import time
 
       start_all()
       # simulate manually editing root credentials file
       machine.wait_for_unit("multi-user.target")
-      machine.copy_from_host("${credsPartial}", "${rootCredentialsFile}")
-      time.sleep(3)
       machine.copy_from_host("${credsFull}", "${rootCredentialsFile}")
 
       machine.wait_for_unit("minio.service")