Add pytest and pytest-cov to dev env

pyproject.toml

@@ -5,3 +5,9 @@ description = "Add your description here"
 readme = "README.md"
 requires-python = ">=3.14"
 dependencies = []
+
+[dependency-groups]
+dev = [
+    "pytest>=9.0.2",
+    "pytest-cov>=7.0.0",
+]