Use single worker for tests because sequence does not support schema

Author: rad-pat

setup.cfg

@@ -61,7 +61,7 @@ ban-relative-imports = True
 inline-quotes = "
 
 [tool:pytest]
-addopts= --tb native -n4 -v -r fxX --maxfail=25 -p no:warnings
+addopts= --tb native -n1 -v -r fxX --maxfail=25 -p no:warnings
 python_files=tests/*test_*.py
 # python_functions=test_round_trip_same_named_column
 # log_level=DEBUG