remove unneeded broadcasting

Author: juan.lopez.arriaza

pymc/distributions/continuous.py

@@ -3728,7 +3728,6 @@ def dist(cls, mu=0, sigma=1.0, *args, **kwargs):
         return super().dist([mu, sigma], *args, **kwargs)
 
     def get_moment(rv, size, mu, sigma):
-        mu, sigma = at.broadcast_arrays(mu, sigma)
         mean = mu + sigma * (np.euler_gamma + at.log(2))
 
         if not rv_size_is_none(size):