OK, there is a solution to your 'problem' but it's not pretty and I probably shouldn't be encouraging this; but I'll throw it out there to clear the air.
That Suntour fork, like many entry-level forks, is a 'one-sided' affair - - meaning that there is a spring in only one fork leg. In most cases, the other leg is devoted to damping circuitry/cartridge/whatever. Not sure the XCT even has damping but whatever. The left leg (the one whith the preload adjuster) holds the spring. It's accessed by removing the large hex-headed cap on top of the stanchion. There is no need to pull apart the fork (i.e. - separate the lowers from the stanchions, as awful so awfully suggested) to get at the spring. Yes it's conceivable (as Daspydyr says) to drop something rigid in there to take up the space the spring did to "lock out" the fork permanently. I would probably choose something like a length of 1/2" dia. 6061 T6 aluminum rod. Just be sure it's long enough to take up ALL the slack.
Having said all of the above, I repeat that I AM NOT RECOMMENDING that you do that. I'm merely pointing out that it is something that could be done with minimal concern for safety. But, honestly wle, it's an ugly, cludgy fix to a non-existent problem. If you want to buy a bike with a suspension fork: 1) learn to ride it with the suspension fork; 2) get it and buy a properr rigid fork for it; or 3) look at a different bike. Quit whining on here that nobody's helping you do something dumb.
Originally Posted by Mark Twain
"Don't argue with stupid people; they will drag you down to their level and then beat you with experience."