Normally you do not want to run ethernet wire anywhere near electrical because of the interference. It is also a electrical code violation in most areas.....this is a safety thing not so much a function thing,
Since the electrical wire is in a armored conduit it likely is ok. The armor will protect from contact as well as reduce any interference.
I would look for cat5e direct bury outdoor cable. This is designed for direct contact with the ground and sun. Both will damage the plastic in normal ethernet cable and then water can mess stuff up.
Cat6 cable buys you nothing extra you would use cat6a if you were going to run 10gbit. I also would avoid shielded cable especially when going between buildings. The shield must be grounded properly and if it is not it actually makes things worse. In addition when you have remote building you increase your risk of different ground levels so you run the increase risk of a ground loop. That also causes issues with your equipment..... this was the hum you used to hear in old audio cables. It is just not worth all the difficultly installing it properly when the benefit is almost non existent.
Key things to watch out for is fake cable. The main fake cable you find in outdoor cable is CCA cable. You want pure copper cable. You also need to be sure the wire size is 22-24 but I have not see outdoor cable that was that crappy flat cable with the tiny wires.