Update timely_beliefs/beliefs/classes.py

Co-authored-by: Felix Claessen <30658763+Flix6x@users.noreply.github.com>

Author: BelhsanHmida

timely_beliefs/beliefs/classes.py

@@ -1228,7 +1228,7 @@ def most_common_event_frequency(self) -> timedelta | None:
         """
         # If data is perfectly regular, reuse inferred frequency
         freq = self.event_frequency
-        if freq is not None and not pd.isna(freq):
+        if not pd.isna(freq):
             return freq
 
         event_starts = pd.to_datetime(self.event_starts.unique())