ClusterFuzzLite build broken since dropping Python 3.11: base-builder image ships 3.11, requires-python is >=3.12

[cohenrobinson]

Summary

The fuzz (address, 30s) ClusterFuzzLite check fails on every PR against current main. It fails at build time — no fuzz target ever runs, so the job provides no fuzzing coverage at all right now.

+ pip3 install --no-cache-dir .
ERROR: Package 'aemo-mdff-reader' requires a different Python: 3.11.13 not in '>=3.12'
root - ERROR - Building fuzzers failed.

Cause

feat!: drop Python 3.11 support (#70) raised requires-python to >=3.12 (pyproject.toml:22), but the ClusterFuzzLite builder runs the oss-fuzz-base/base-builder-python image, which ships Python 3.11.13. .clusterfuzzlite/build.sh does pip3 install . against that interpreter, which now refuses the package.

This is consistent with the history: fuzz runs were green on every dependabot base-builder bump before #70 landed, and have failed since.

Why it matters

• It is not a required status check, so it doesn't block merges — which makes it easy to normalise as "the fuzz one always fails" and miss a genuine crash later.
• Fuzzing coverage is currently zero despite the job appearing to run.

Possible fixes

1. Pin the fuzz job to a base-builder-python variant with Python >= 3.12 (may need an upstream image that ships it).
2. Install with an interpreter override / build the fuzz env from a 3.12 base rather than the stock image.
3. If the stock image is stuck on 3.11 for now, relax requires-python only for the fuzz build (undesirable — it would diverge from the shipped package).

Option 1 is the clean one if a suitable image tag exists; the SHA pin + dependabot convention in .clusterfuzzlite/ would carry over unchanged.