Why do I have a .subversion folder hidden in my home folder on mac OS?
Why not make a Time Machine backup and delete it? It’s a common code control tool and any number of packages could use it to manage the software changes in your home directory without even going into if it’s not actually subversion and instead malware.

You would figure out how it was created by looking at snapshots of backups and also using the mdls tool to examine all the date related metadata and origin of each file in that folder. The modification and creation dates of the files will clue you in to how recent the files are and help you see if it’s something currently running or perhaps just migrated in from a long time ago on an old computer.