fix: use pyproject.toml pythonpath instead of sys.path hack

Author: skyoo2003

pyproject.toml

@@ -0,0 +1,2 @@
+[tool.pytest.ini_options]
+pythonpath = ["."]

tests/compatibility/test_conftest_helpers.py

@@ -1,8 +1,4 @@
 import io
-import os
-import sys
-
-sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", ".."))
 
 from tests.compatibility.conftest import _build_devcloud_cmd, _start_server_error