fix: adjust incremental loader to find the largest chain

[thesayyn]

Fixes the incremental loader to find the largest chain in the layers and start loading from there.

[aspect-workflows]

Test

All tests were cache hits

28 tests (100.0%) were fully cached saving 28s.

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Lint

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3 issues require fixes
1 issues can be fixed automatically

💡 Auto-fix linting errors with:

bazel lint //oci_python_image/hello_world:test_container --fix

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Format

[aspect-workflows]

Ruff provided a suggestion

Suggested change

	import os
	import io
	import logging
	import hashlib
	import io
	import logging