fix pytest v9 typing issue

CHANGELOG.md

@@ -1,6 +1,11 @@
 # Changelog
 All notable changes to this project will be documented in this file. If you make a notable change to the project, please add a line describing the change to the "unreleased" section. The maintainers will make an effort to keep the [Github Releases](https://github.com/NREL/OpenOA/releases) page up to date with this changelog. The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## v3.1.4 - 2025-12-01
+
+- During the custom test collection, convert the `Path` objects to `str` to avoid issues with the
+  type enforcement of `list[str]` for `args` in Pytest v9.
+
 ## v3.1.3 - 2025-01-31
 
 - Pin SciPy to >= 1.7 and <1.14 to avoid an incompatibility error with PyGAM.

openoa/__init__.py

@@ -1,4 +1,4 @@
-__version__ = "3.1.3"
+__version__ = "3.1.4"
 
 """
 When bumping version, please be sure to also update parameters in sphinx/conf.py

test/conftest.py

@@ -25,8 +25,8 @@ def pytest_configure(config):
     regression = config.getoption("--regression")
 
     # Provide the appropriate directories
-    unit_tests = [el for el in (ROOT / "unit").iterdir() if el.suffix == ".py"]
-    regression_tests = [el for el in (ROOT / "regression").iterdir() if el.suffix == ".py"]
+    unit_tests = [str(el) for el in (ROOT / "unit").iterdir() if el.suffix == ".py"]
+    regression_tests = [str(el) for el in (ROOT / "regression").iterdir() if el.suffix == ".py"]
 
     # If both, run them all; if neither skip any modifications; otherwise run just the appropriate subset
     if regression and unit: