I noticed that in the changelogs for the game, a lot of glitches seemingly useful in speedrunning seem to have been patched. Are there old versions uploaded somewhere that we can run or am I out of luck?

What glitches you talking about? All Glitches are still possible, the only thing that changed is that you have to wait 2-3 seconds till you can sleep again

If you look at the changelog, you'll see that several bugs were patched out. The one that stands out to me is the infinite clay glitch. Some tiles would always drop clay, so you could Hoe the dirt, then Pickaxe it to return it to normal, then Hoe it again to get more clay. Simple things like this were in the game in earlier versions but were eventually patched out. I believe this is what Ipquarx is talking about