[Bug] found a bug with handling choices

[RevanthRameshkumar]

fsm = interegular.parse_pattern("(not(?=\s)|not(?=\()|-)").to_fsm()
assert fsm .accepts('-') == True
assert fsm .accepts('--') == False

Both of the above fail. I expect the first to succeed and the second to fail, because the final state for the second should end at the first '-'.

In contrast:

re.match('(not(?=\s)|not(?=\()|-)', '-') 
re.match('(not(?=\s)|not(?=\()|-)', '--') 

both of the above succeed (but the span for the second one is still (0, 1)