Handle IO errors when checking existing rig.json

[alexpiet]

Pull Request instructions:

• Please follow the update protocol
• Answer the questions below in detail. Your responses will be emailed to experimenters.
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• If computer maintainers need to manually update anything, provide detailed step by step instructions
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Describe changes:

Previously, when creating a rig metadata, we wrote the new metadata to file, then loaded it back. We then compared this with the existing rig metadata which was loaded to file. We did this to ensure serialization/deserialization happened consistently with the old and new. This created I/O errors when the new file didn't finish writing by the time it was loaded back. So now I just serialize/deserialize in python without writing to disk.

What issues or discussions does this update address?

• resolves https://github.com/AllenNeuralDynamics/aind-behavior-blog/issues/406
• resolves https://github.com/AllenNeuralDynamics/dynamic-foraging-task/issues/488

Describe the expected change in behavior from the perspective of the experimenter

Should limit uncaught errors about JSON decoding

Describe any manual update steps for task computers

• none

Was this update tested in 446/447?

• [x] tested on my laptop
• [ ] tested in 447

[alexpiet]

@hanhou @XX-Yin this is ready for review