drop useless test_update test

This test was not finished by me?
Now it's going to be broken by lassulus.

pkgs/clan-cli/tests/test_machines_update_cli.py

@@ -1,35 +0,0 @@
-import os
-import shutil
-from pathlib import Path
-from tempfile import TemporaryDirectory
-
-import pytest
-from host_group import HostGroup
-
-
-def test_update(
-    clan_flake: Path, host_group: HostGroup, monkeypatch: pytest.MonkeyPatch
-) -> None:
-    assert len(host_group.hosts) == 1
-    host = host_group.hosts[0]
-
-    with TemporaryDirectory() as tmpdir:
-        host.meta["flake_uri"] = clan_flake
-        host.meta["flake_path"] = str(Path(tmpdir) / "rsync-target")
-        host.ssh_options["SendEnv"] = "REALPATH"
-        bin = Path(tmpdir).joinpath("bin")
-        bin.mkdir()
-        nixos_rebuild = bin.joinpath("nixos-rebuild")
-        bash = shutil.which("bash")
-        assert bash is not None
-        nixos_rebuild.write_text(
-            f"""#!{bash}
-exit 0
-"""
-        )
-        nixos_rebuild.chmod(0o755)
-        f"{tmpdir}/bin:{os.environ['PATH']}"
-        nix_state_dir = Path(tmpdir).joinpath("nix")
-        nix_state_dir.mkdir()
-
-        monkeypatch.setenv("REALPATH", str(nix_state_dir))