ci: remove obsolete PyPTO PTO-ISA pytest option

[mouliangyu]

Summary

• stop passing the removed --pto-isa-commit option to PyPTO simulator pytest runs
• keep the existing explicit PTO-ISA checkout and PTO_ISA_ROOT wiring unchanged

Background

PyPTO commit 86549ddd removed the --pto-isa-commit pytest option. Because this workflow checks out PyPTO main, pytest now exits during argument parsing before collecting any simulator test:

error: unrecognized arguments: --pto-isa-commit=...

This caused the vpto-sim-validation job to fail independently of the PTOAS change under test.

Validation

• git diff --check
• parsed .github/workflows/ci_sim.yml with PyYAML
• ran PyPTO's hello-world simulator test with the remaining workflow arguments and --collect-only (1 test collected)

[gemini-code-assist]

Note

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