fix: Use Pandas Series instead of numpy array to ensure type compatibility

Author: effigies

src/bids/variables/variables.py

@@ -413,7 +413,7 @@ def to_dense(self, sampling_rate=None):
         duration = math.ceil(  # Round up to nearest second
             round(bin_sr * self.get_duration(), 3)  # Cut off at millisecond precision
         )
-        ts = np.zeros(duration, dtype=self.values.dtype)
+        ts = pd.Series(0, index=np.arange(duration), dtype=self.values.dtype)
 
         onsets = np.round(self.onset * bin_sr).astype(int)
         durations = np.round(self.duration * bin_sr).astype(int)
@@ -446,7 +446,6 @@ def to_dense(self, sampling_rate=None):
             source=self.source,
             sampling_rate=sampling_rate)
 
-
         return dense_var
 
     def _extract_entities(self):