deprecate the method _load_class_info

To refactor the following when dealing with annotations:
- running of CANOPUS to predict chemical classes
- loading chemical classes to annotate spectra and moleclar families

src/nplinker/loader.py

@@ -1,6 +1,7 @@
 import glob
 import os
 from pathlib import Path
+from deprecated import deprecated
 from nplinker.class_info.chem_classes import ChemClassPredictions
 from nplinker.class_info.class_matches import ClassMatches
 from nplinker.class_info.runcanopus import run_canopus
@@ -197,9 +198,6 @@ def load(self):
         if not self._load_genomics():
             return False
 
-        if not self._load_class_info():
-            return False
-
         self._load_optional()
 
         # Restrict strain list to only relevant strains (those that are present
@@ -519,6 +517,7 @@ def _run_bigscape(self):
 
                 self.bigscape_dir = find_bigscape_dir(self.bigscape_dir)
 
+    @deprecated(reason="To be refactored. It was used in the `self.load` method before.")
     def _load_class_info(self):
         """Load class match info (based on mibig) and chemical class predictions.