use pathlib more frequently

tests.py

@@ -36,14 +36,14 @@ def test_prepare_environment(tmp_path):
     assert not script_dir.exists()
 
     result = mod.prepare_environment(
-        mpsd_release=mpsd_release_to_test, script_dir=str(script_dir)
+        mpsd_release=mpsd_release_to_test, script_dir=(script_dir)
     )
     # wait for 20 seconds for the git clone to finish
     # time.sleep(20)
     # check if the directory now is created
     assert release_base_dir.exists()
     # check for spack-environments directory
-    assert spack_environments in os.listdir(str(release_base_dir))
+    assert spack_environments in os.listdir(release_base_dir)
     # check if the git branch is correctly checked out
     assert (
         subprocess.run(
@@ -71,7 +71,7 @@ def test_setup_log_cmd(tmp_path):
 
     # run the prepare_env functionality
     mod.prepare_env(
-        toolchain_base_dir=str(tmp_path),
+        toolchain_base_dir=(tmp_path),
         mpsd_spack_ver="dev-23a",
         skip_dir_check=False,
         shared_var=shared_var,
@@ -81,6 +81,7 @@ def test_setup_log_cmd(tmp_path):
     assert os.path.exists("logs/install-software-environment.log")
     assert os.path.getsize("logs/install-software-environment.log") > initial_bytes
 
+
 def test_install_environment(tmp_path):
     # Expect and Exception when wrong toolchains are provided
     with pytest.raises(Exception):