fix: update hash method to use bytes representation for values

Author: jonas-eschle

src/hepstats/hypotests/parameters.py

@@ -84,7 +84,7 @@ def __eq__(self, other):
         return values_equal.all() and name_equal
 
     def __hash__(self):
-        return hash((self.name, self.values.tostring()))
+        return hash((self.name, self.values.data.tobytes()))
 
     @property
     def ndim(self):