Add pytest marker to neutron_pd_cwl_lbco_crysfml test

Author: AndrewSazonov

tests/integration/fitting/test_switch-calculator.py

@@ -3,12 +3,14 @@
 
 import tempfile
 
+import pytest
 from numpy.testing import assert_almost_equal
 
 
 TEMP_DIR = tempfile.gettempdir()
 
 
+@pytest.mark.fast
 def test_neutron_pd_cwl_lbco_crysfml(tmp_path) -> None:
     import easydiffraction as ed