I recall hearing of an Economics professor who gave the same test every year. When it was objected that the students had access to the old tests, he explained, “
Yes, but in Economics we change the answers each year.”
Same could be said about philosophy

On a slightly OT note, my friend got an A for his A-level in philosophy simply by replying to a question that asked them to describe the chair in front of them simply by giving the two word answer ‘what chair?’ LOL
Back on topic, a lot of study aid books you get will teach you by using old set questions so you can start thinking in that way. If you’re taking the questions and studying based on them and so learning in the process, then I don’t see that as a bad thing. Education is about learning and retaining the information, you’re tested just to make sure you’ve actually learnt it. In a similar response to someone else, I was also always told by my teachers and lecturers to keep everything and to get your information where ever you can.
So long as it’s not the actual test and actual questions you’ll be given, I wouldn’t consider it cheating, just preparation. And I’m not sure it’s the same where you are, but here exams are required to be changed, for this very reason.
But at the end of the day, you should follow your conscience. If something is niggling at you about it, saying this isn’t right, and I think it might be if you’ve come on here to ask about it, then maybe it’s best to follow your gut instinct so you can feel right about it rather than guilty and worried.