add sliding window support for Gemma3

[lanluo-nvidia]

Description

Currently It is only working, if I create the sliding window attention_mask in torch_tensorrt.
Need to further investigate why it is not working when use the attn_mask transformers passed in.

Another alternative is try to figure out how we can get the configuration on the sdpa op level.
This way we can create the sliding window attention_mask with user configured sliding window.

Fixes # (issue)

Type of change

Please delete options that are not relevant and/or add your own.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project (You can use the linters)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas and hacks
• I have made corresponding changes to the documentation
• I have added tests to verify my fix or my feature
• New and existing unit tests pass locally with my changes
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