fix: add reflections to pip package

[inimaz]

Solves #8608.

Setup.py was not taking into consideration the flatbuffers.reflection package.
Adding it via find_packages().

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[inimaz]

Hello @dbaileychess, I signed the cla (the check is passing now). Tell me if something is missing thanks!

[jtdavis777]

@fliiiix -- do you know if there's any history or lore as to why reflection isn't packaged with the flatbuffers package?

[jtdavis777]

@inimaz are all the updates in the reflection folder a result of new code gen?

[fliiiix]

@fliiiix -- do you know if there's any history or lore as to why reflection isn't packaged with the flatbuffers package?

No unfortunately not and I don't use reflection myself