[IntegTest]add sharding optimization integ tests

[HappyAmazonian]

Description

add Multinode sharding integ test as we start to migrate neo tests here

Type of change

Please delete options that are not relevant.

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

Checklist:

• Please add the link of Integration Tests Executor run with related tests.
• Have you manually built the docker image and verify the change?
• Have you run related tests? Check how to set up the test environment here; One example would be pytest tests.py -k "TestCorrectnessLmiDist" -m "lmi_dist"
• Have you added tests that prove your fix is effective or that this feature works?
• Has code been commented, particularly in hard-to-understand areas?
• Have you made corresponding changes to the documentation?

Feature/Issue validation/testing

I ran the integration test using this change
https://github.com/deepjavalibrary/djl-serving/actions/runs/13381188448

https://github.com/deepjavalibrary/djl-serving/actions/runs/13422181704/job/37499275188