A question about rear braking pads on Gen 3

I bought my Prius 3 18 months ago from Germany and no problems with it thanks God.

But two weeks ago after a 25 km trip to my brother-in-law when I stopped the car I smell a flavor of hot plastic/asbestos/something like that. I touch my left rear rim and was hot. I touch the left rear rotor and was even much hotter.

OK, looks like a stuck pad I said. Push the brake pedal a couple of time and the parking brake too. After that all seems OK but I was intrigued so last Saturday I wanted to look what's happened there.
My guess was a stuck sliding pin or/and a bad piston mounting (not in that X position).

Indeed it was an (almost) stuck pin. The upper one was fine I can move it with my fingers but the bottom one was very hard to move.
I've lubricate them, mount them back and everything looks good.

But I have a problem with my outside pad. It is worn uneven. Probably because of the upper slide pin which was fine pad was used more on the upper side than bottom so now I want to change them all and here comes my question.
In all the videos/pictures I saw pads have a V-shape spring attached to them (anti-squeal I guess). This one.

I don't have it and my pads don't have the holes to mount them.
So my question is are two types of pads, one with holes for that V-shape springs and ones without those holes?
Now without that V spring my brakes are fine, no noise/squeal/whatever so my question is can I mount another pad set without that V spring?

Thanks.

 

Thanks.
I already bought a set of pads without holes and I'll see how it goes after I'll mount them.

Now I can spin the wheel a couple of rotations with no visible drag. Hope that new ones will act the same.