If you are looking for very light weight, people speak highly of the ripstop dance pants, but I don't know how breathable they are. Nylon can be hot and clammy.
https://www.amazon.com/Rip-Stop-Pant-701BLKL-Black-Large/dp/B00L8W76Q0
Aliexpress has even lighter ones, but they are nearly transparent in the white version. In black, they are tolerable -- but still made of nylon, and not very breathable.
https://imgur.com/a/K7wEJ#oYjNJV1
For breathability, the Columbia Silver Ridge pants are supposed to be pretty good. They now come in a stretch version, which should make for better mobility. Weight, 14 oz.