fix the error not display when yaml file is incorrect

Signed-off-by: reid_liu <guliu@redhat.com>

Author: reidliu41

src/instructlab/schema/taxonomy.py

@@ -429,6 +429,6 @@ def parse(self, path: str | pathlib.Path) -> Taxonomy:
 
             self._schema_validate(text=text, taxonomy=taxonomy)
         except Exception as e:
-            raise TaxonomyReadingException from e
+            raise TaxonomyReadingException(f"{e}") from e
 
         return taxonomy