No, if there’s nothing, it’s not using one of the big DRM systems.
The only way to know for sure is to install it and try to run it without Steam (rename Steam dir and Steam exe just in case). Some games use Steam DRM or otherwise rely on Steam, so this is to rule those out too.
ayyy@sh.itjust.works 2 hours ago
Also if you prefer a more thorough listing, check out the “Detected Technologies” section of SteamDB. I just chose a random game as an example of something with just Steam drm. steamdb.info/app/2062430/info/