[skyrl-train] Add GMPO #834
Description
Add GMPO from: https://arxiv.org/abs/2507.20673 as a new policy loss type.
Verl PR: volcengine/verl#2795
{{ message }}
Add GMPO from: https://arxiv.org/abs/2507.20673 as a new policy loss type.
Verl PR: volcengine/verl#2795