Replaced two raise ..., ... by raise ...(...) in the spirit of #15990

before this patch, so two more such issues introduced by this patch have
been modified in order to avoid potential future painful merge conflicts.

src/sage/combinat/finite_state_machine.py

@@ -6056,7 +6056,7 @@ def process(self, *args, **kwargs):
                 return (it.accept_input, it.current_state, it.output_tape)
         else:
             if not it.accept_input:
-                raise ValueError, "Invalid input sequence."
+                raise ValueError("Invalid input sequence.")
             return it.output_tape
 
 
@@ -6416,7 +6416,7 @@ def get_next_transition(self, word_in):
         for transition in self.current_state.transitions:
             if transition.word_in == word_in:
                 return transition
-        raise ValueError, "No transition with input %s found." % (word_in,)
+        raise ValueError("No transition with input %s found." % (word_in,))
 
 
 #*****************************************************************************