move tests that do not need file system out of chdir context

tests.py

@@ -26,10 +26,13 @@ def test_os_chdir(tmp_path):
 
 
 def test_run_method(tmp_path):
+    run = mod.run
+
+    # test a command with options:
+    assert run(["date", "+%Y-%m-%d"]).returncode == 0
+    assert run("date +%Y-%m-%d", shell=True).returncode == 0
+
     with mod.os_chdir(str(tmp_path)):
-        run = mod.run
-        # test a command with options:
-        assert run(["date", "+%Y-%m-%d"], shell=True).returncode == 0
         # ensure single string command works
         assert run(("ls -l")).returncode == 0
         # test spaces are handled correctly: