ISSUE-18533: [Enhancement] Support reading config options from file in Function Python Runner

[sijie]

Original Issue: apache#18533

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Motivation

Currently the python runner uses argparse to parse command line args. However in certain cases reading from command line is not very flexible (think we need to use a env var as an argument but the container has no shell access). Thus we need to support reading configs from a file.

This is necessary for :

• update replicas will cause all pods been rescheduled function-mesh#368
• Build distroless package for better security, smaller size, speed and more function-mesh#448

Solution

No response

Alternatives

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Anything else?

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Are you willing to submit a PR?

• I'm willing to submit a PR!