try rerunning tests on CI rather than skipping

tests/pipeline/test_statistical.py

@@ -123,7 +123,6 @@ def init_class_fixtures(cls):
 
     # todo: figure out why this fails on CI
     @parameter_space(returns_length=[2, 3], correlation_length=[3, 4])
-    @pytest.mark.skip(reason="Sometimes fails on CI")
     def test_correlation_factors(self, returns_length, correlation_length):
         """
         Tests for the built-in factors `RollingPearsonOfReturns` and
@@ -643,7 +642,6 @@ def compute(self, today, assets, out):
 
     # todo: figure out why this sometimes fails on CI
     @parameter_space(returns_length=[2, 3], regression_length=[3, 4])
-    @pytest.mark.skip(reason="Sometimes fails on CI")
     def test_factor_regression_method(self, returns_length, regression_length):
         """
         Ensure that `Factor.linear_regression` is consistent with the built-in