[BugFix] Fix batch_size derivation and relax shape checks in SM90 flash_mask_attn#7210

Jiang-Jia-Jun merged 4 commits intoPaddlePaddle:developPaddlePaddle/FastDeploy:developfrom

xiaoxiaohehe001:fix_flash_mask_attn_sm90xiaoxiaohehe001/FastDeploy:fix_flash_mask_attn_sm90Copy head branch name to clipboard