Trying to use test_pir branch, would be great with a beta

[nicklasb]

Problem description
I have a GPU/PaddleDetection setup that for some reason seem to only work with paddle>=3.0.0*, and I need to export the model, and I am not finding a working pip-build-setup, and building locally is a bit of hassle, actually I am not getting it to build either on Windows or Linux.

Is there a beta with .json model beta support on the way anytime soon?

Note also that FLAGS_enable_pir_api=0 on the export_model causes an error (TypeError: Cannot interpret '<VarType.FP32: 5>' as a data type), not sure if it worth finding out..