MelindaandBill Gates have parted ways once again. The Microsoft founder’s ex-wife, 59, resigned as co-chair of The Bill & Melinda Gates Foundation this week, and she’s $12.5 billion richer for the decision, RadarOnline.com has learned. Melinda and Bill — who went through a nasty and speedy divorce in 2021 — founded the organization in 2000. The now exes built it into one of the biggest private foundations, with an $8.6 billion budget for 2024. Melinda’s last day with the organization will be June 7. Once she departs, Bill will become its sole chair, according to the organization on Monday. She…