Update version of onnx used by onnx-mlir

[cjvolzka]

We're currently using onnx 1.11. The current version of onnx is 1.12. The primary end goal is to update to a version of onnx that includes includes onnx/onnx#4544 (once it merges).

[AlexandreEichenberger]

Added Tong and Philip as likely candidate to upgrade our opset to the latest (17). According to a quick read of the operators, there is only a few new operators and no functionality change for existing ones, so it should be easy to add these new ops as unsupported yet.

Moving to the latest ONNX would fix a vulnerability reported in the onnx/onnx issue/pr

[philass]

I can likely add support for the ingestion of opset 17 by the end of next week

[cjvolzka]

Closing as duplicate of #1808