Specify dtype as int32 for paddle.cumsum due to API Change

[DrRyanHuang]

Paddle#74625 (合入时间8月20号9点) 引入后，paddle.cumsum 输出值 cum_offsets 的默认 dtype 是 int64，不再是 int32

后面自定义算子中存在按照 int32 类型解析的逻辑，存在问题

cum_offsets.data<int>(),

本PR将必要的 paddle.cumsum 参数 dtype 指定为 int32

PS:

目前CI上 FD develop 分支是锁的 python -m pip install paddlepaddle-gpu==3.0.0.dev20250818 -i https://www.paddlepaddle.org.cn/packages/nightly/cu126/ 这个 paddle 版本

cc @SigureMo

[paddle-bot]

Thanks for your contribution!

[codecov-commenter]

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