Welcome to the Forum.
Quite often ANY assembly line production item, (gun or otherwise,) has looser tolerances than any custom made product. As such, you can have parts rub together like shown above. Not a huge issue.
As mentioned, do a simple field stripping, (you do have the manuel don't you? If not Ruger will send one for free.)
Then, look inside the frame in the area where the trigger goes. We call this the trigger slot.
On the inside, especially the sides of the slot, you may find some small burrs of metal sticking out. It might require magnification to see. The act of "stoning" that area means to polish those little burrs away. VERY small amounts are all that is usually necessary. As mentioned above, go slow & check the job often until it's stopped.
I hope this helps!