In addition to Zombimode's excellent points, there's also an important difference in ethos. At no point in Star Trek is there any doubt in the overarching narrative that the superpowerful deity like beings are actually powerful or very strange aliens (the one real exception is that the Bajorans believe that the beings in the wormhole are deities but even Sisko who is their Emissary doesn't think that). In contrast, the Force is generally inherently mystical, least until Episode One where they added Midichlorians. But even that shows the difference in approach; fans were furious about Midichlorians, but when Beverly Crusher mentions specific proteins and molecules associated with telepathy, fans don't really mind at all. Similarly, when the right sort of technobabble particle beam turns out to be fatal to the wormhole aliens because of their nature, no fans had any issue with it. Star Trek is ultimately an explicable universe, and that helps push it much further into the scifi category.
A tangent on the tangent: The lines between scifi and fantasy are very blurry, and many categories in life have inherently blurry boundaries (heck even for whether or not two creatures are the same species is a really difficult problem), and it isn't necessarily productive to have conversations about such blurry boundaries because they often say more about one's personal intuition than much else. In so far as it is useful, it is important then to acknowledge that one can have many different aspects some of which point in one direction and some of which point in another, and it may then be helpful to then see what direction most of the weight lies.