Fixing flex attention for torch=2.6.0
Author: salmanmohammadi
Pull request: yes
Labels: name: for patch

# What does this PR do?

This PR fixes this issue originally raised in pytorch core https://github.com/pytorch/pytorch/issues/146260 for flex attention on 2.6.0, by setting `mode="max-autotune-no-cudagraphs"`. 
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Fixes # (issue)


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Comments:
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Seems like the llama4 addition changed flex compilation #37307 😄 

Flex was not working for decoding!