csound-expression.cabal: Reduce version of temporal-media

[rvl]

temporal-media-0.6.4 doesn't exist on Hackage, nor does it exist at the source repository.

I'm assuming the change from 0.6.3 to 0.6.4 was just a typo which happened while bumping cabal versions for the csound-expression 5.4.4.1 release.

[anton-k]

yeah, that's fixed in my local branch. I forgot to push it upstream