Add cli tests to workspace pythonpath

Every other package had its tests/ directory in
pythonpath; cli was the only one missing, making
its conftest imports rely on rootdir discovery.

Author: sethfitz

pyproject.toml

@@ -61,6 +61,7 @@ pythonpath = [
     "packages/overture-schema-annex/tests",
     "packages/overture-schema-base-theme/tests",
     "packages/overture-schema-buildings-theme/tests",
+    "packages/overture-schema-cli/tests",
     "packages/overture-schema-core/tests",
     "packages/overture-schema-divisions-theme/tests",
     "packages/overture-schema-places-theme/tests",