[BugFix] Fix preemption out of real_bsz

[rainyfly]

Motivation

判断当前请求槽位的索引大于 real_bsz 时，应该是>，而不是>=。

Modifications

None

Usage or Command

None

Accuracy Tests

None

Checklist

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[paddle-bot]

Thanks for your contribution!

[Copilot]

Pull request overview

这个PR修复了一个抢占调度逻辑中的边界条件判断错误。当判断请求槽位索引是否超出实际批次大小时，将比较运算符从 >= 修正为 >，避免了最后一个有效槽位（索引为 batch_size - 1）的请求被错误地重调度。

• 修正了 _reschedule_preempt_task 方法中的索引越界判断逻辑
• 将条件从 idx >= (batch_size - 1) 改为 idx > (batch_size - 1)

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
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Additional details and impacted files

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