This is not a recommendation but if you are brave and good with the possibility of causing major damage to your engine or more likely I'd guess an unexpected end to a ride some day.
First; tape up the oil port really good.
Remove the bolt. Use a new bolt of proper size and length. Measure the depth of the hole, if necessary cut a bolt to get the length very close to the hole depth. Go buy a bottoming tap, probably a few bux at the local auto supplier and worth having in the tool box. You can also grind the end off a regular tap to make a bottoming tap. Carefully run the tap into the hole, use a smidge of grease or wax to help any thread cutting go smoothly. Remove, use your new bolt and some blue thread lock.
this form might be good...
get a bit under the bolt head also.
Put in the new bolt and ever so gently snug it, knowing to stop at just the precise moment BEFORE the threads start to strip.
In a similar situation I have been known to cut a narrow strip of pop can, insert it in the hole, install the bolt nearly home, knife off any of the strip sticking out before the bolt head comes in contact with the cylinder, finish tightening. Hope that stops the leak and holds.
I suppose you could remove that steel insert, helicoil or thread sert the tensioner and put it back together. Controlling depth will be critical.