onnx 1.21.0 upgrade: fix IR version 13 incompatibility with onnxruntime

Problem

PR #223 bumps onnx from 1.18 to 1.21.0. CI fails with 63+ test failures across test (analyze) and test (optim) jobs.

Root cause

onnx 1.21.0 changed helper.make_model() to default ir_version to 13 (was 8/9 in 1.18). onnxruntime only supports up to IR version 11, so any code path that creates a model and runs it through ORT fails with:

Unsupported model IR version: 13, max supported IR version: 11

CI failures

test (optim) — 3 failures

• tests/unit/optim/fusions/test_fusion_rmsnorm.py — TestNumericEquivalence (3 tests)
• 5 make_model() calls without ir_version set (lines 70, 121, 265, 304, 340)

test (analyze) — 60+ failures

• tests/unit/analyze/test_input_generators.py — test_operator_validation for all opsets (17, 22, 23)
• Root: src/winml/modelkit/pattern/op_input_gen/op_input_gen.py:1017 — _create_model() has no ir_version set
• validate_inputs() → _run_op_on_cpu() creates ORT session → IR version 13 rejected

Fix needed

Add model.ir_version = 11 (or 8 for tests) after make_model() in these locations:

Source code (2 files):

Test code (1 file):

Note: 80+ other test files also have make_model() without ir_version, but don't currently fail because they don't run ORT inference. Consider a sweep to future-proof.

Related

• PR #223 (dependabot/pip/onnx-1.21.0)