fix(peft): enable v5 expert adapters for Nemotron and MiniMax (#3439)

* fix(peft): enable v5 adapters for Nemotron and MiniMax

Signed-off-by: Yuhe Zhang <yuhez@nvidia.com>

* fix(peft): align MoE adapter reload namespaces

Signed-off-by: Yuhe Zhang <yuhez@nvidia.com>

* fix(ci): correct MoE robustness overrides

Signed-off-by: Yuhe Zhang <yuhez@nvidia.com>

* fix(ci): use built-in MiniMax for PEFT reload

Signed-off-by: Yuhe Zhang <yuhez@nvidia.com>

* fix(peft): include MiniMax expert adapters

Signed-off-by: Yuhe Zhang <yuhez@nvidia.com>

* fix(peft): guard v5 expert metadata

Signed-off-by: Yuhe Zhang <yuhez@nvidia.com>

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Signed-off-by: Yuhe Zhang <yuhez@nvidia.com>