You are worrying way too much about a tiny bubble. Keep the ski out of the sun and it will be fine.
It's not an aircraft spar which will go through millions of load cycles. Even if it were, the bubble is way out on the ski and not heavily loaded. Structurally, the chances are good that the ski will outlast you.
Skis are typically skins of carbon or fiberglass cloth wetted with resin and sandwiched over a foam core. Pressure is applied in a mold to form the desired shape while the resin cures. A defect in the mold can cause a thickening bump but that doesn't look like a mold defect.
Your bubbles are probably voids in the lamination. Somewhere after it was out of the mold the bubble formed. I've had skis that molded in trapped air bubbles, been too little resin and not bonded to the core, overheated and pulled the skins from the core, and been dinged. Lots worse than that - and haven't caused a break.
To repair that bubble, I'd cut a hole in the top of the bubble, work some epoxy inside, heat it, clamp it and add some more heat. If I overtighten the clamp, some filler might be needed to level things out once everything has cured.
The last bubbles I fixed, I used Gorilla glue (a foaming polyurethane glue). The Gorilla glue flowed more easily into the void but I had to put water on the repair to get it to cure. Clamping was not called for in this case as my voids were collapsed - not sure that the Gorilla glue would have cured under clamps. My repair looks OK. I will have to see how it lasts vs epoxy.
Eric