fix: get_hash function for engine caching

[zewenli98]

Description

Reimplemented the get_hash function for engine caching, which fixes the existing bug and is able to deal with isomorphic graphs.

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)

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
• I have added the relevant labels to my PR in so that relevant reviewers are notified

[lanluo-nvidia]

LGTM
the test are failing due to the upstream torch change:pytorch/pytorch#140085

#3291
once this PR is merged in, please rebase and test this again.

[narendasan]

@zewenli98 please rebase

[narendasan]

LGTM