fix: Updating how to access QuantileDeltaMappingCorrection

Using it as a bias' resource, and doesn't need to know how it is
organized internally.

tests/bias/test_qdm_bias_correction.py

@@ -11,7 +11,7 @@
 from sup3r import CONFIG_DIR, TEST_DATA_DIR
 from sup3r.models import Sup3rGan
 from sup3r.pipeline.forward_pass import ForwardPass, ForwardPassStrategy
-from sup3r.bias.bias_calc import QuantileDeltaMappingCorrection
+from sup3r.bias import QuantileDeltaMappingCorrection
 from sup3r.bias.bias_transforms import local_qdm_bc
 from sup3r.preprocessing.data_handling import DataHandlerNC, DataHandlerNCforCC