Fix issue with finding incorrect conftest file for proto tests (Bears…

…-R-Us#3250)

In certain environments, pytest was finding the incorrect version
of the conftest when running the proto tests. Adding the directory
explicitly to the proto test call fixes this issue.

Makefile

@@ -529,7 +529,7 @@ test-python:
 
 size=100
 test-python-proto:
-	python3 -m pytest -c pytest_PROTO.ini --size=$(size) $(ARKOUDA_PYTEST_OPTIONS)
+	python3 -m pytest -c pytest_PROTO.ini PROTO_tests/ --size=$(size) $(ARKOUDA_PYTEST_OPTIONS)
 
 CLEAN_TARGETS += test-clean
 .PHONY: test-clean