Wiper seals

There are 2 tangs used to lo locate the window gasket that were cut into or out of the cowl. Shaped like \___/ . When that is bent up to create a tang it leaves a hole that size. The gasket and lots of sealant is supposed to seal it. Over time the sealant falls through.
This would be the last place to go. Attack the vent boxes and wiper pivots first and cross your fingers.
If you do take the windshield out, cut out some pieces of aluminum flashing ( coil stock) and cover those holes.