fix(test): add all python paths that don't error

tests/integration/services/conftest.py

@@ -14,22 +14,26 @@
 #
 # For further info, check https://github.com/canonical/charmcraft
 """Configuration for services integration tests."""
+import contextlib
 import sys
 
+import pyfakefs.fake_filesystem
 import pytest
 
 from charmcraft import services
 from charmcraft.application.main import APP_METADATA, Charmcraft
 
 
 @pytest.fixture()
-def service_factory(fs, fake_path, simple_charm) -> services.CharmcraftServiceFactory:
+def service_factory(fs: pyfakefs.fake_filesystem.FakeFilesystem, fake_path, simple_charm) -> services.CharmcraftServiceFactory:
     fake_project_dir = fake_path / "project"
     fake_project_dir.mkdir()
 
     # Allow access to the real venv library path.
     # This is necessary because certifi lazy-loads the certificate file.
-    fs.add_real_directory(sys.path[-1])
+    for python_path in sys.path:
+        with contextlib.suppress(OSError):
+            fs.add_real_directory(python_path)
 
     factory = services.CharmcraftServiceFactory(app=APP_METADATA)