Bump flatbuffers and use internal flatbuffers in ONNXRuntime

[davidrohr]

[davidrohr]

ONNXRuntime does not support any newer version, and will not in the foreseeable future as they say they can anyway do this internal build.

[ktf]

Fair enough, but why bumping it, then? Is it required to get the new GCC working? If yes, how come the internal version does work?

[davidrohr]

That is a good question, I was wondering the same. For me our flatbuffers did not compile with gcc13, while the 9nnx-internal version compiled. I didn't check if they somehow fixed it. Anyhow, I don't like using a many years old version due to onnx decising they do not want to bump...

[ktf]

@davidrohr do you understand the issue on cs8?

[davidrohr]

@ktf : which issue on cs8?

[ktf]

yesterday it was failing. maybe it was simply a glitch in the wrong package.

[davidrohr]

Now Ubuntu fails, but it was green before. So I think it is more random ctests failing. @pzhristov : What is the status of the tests with analysis? Can we merge this?

[ktf]

Yes, indeed ubuntu is unrelated.

[davidrohr]

no longer needed with onnx bumped to 1.18