Split Mixtral test into two scripts

[RissyRan]

Description

Split Mixtral end-to-end test into 2 scripts, and this PR works with XL ML PR.

Tests

Please describe the tests that you ran on Cloud VM to verify changes.

Instruction and/or command lines to reproduce your tests: ... Build image, and upload to Airflow and test.

List links for your tests (use go/shortn-gen for any internal link): ... Airflow test: link XPK test: link