starknet_os: import random EC point logic

[dorimedini-starkware]

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[dorimedini-starkware]

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• starknet_os: import random EC point logic #14195 👈 (View in Graphite)
• release: upgrade rand crate version #14194
• starknet_patricia: change test util random u256 #14193
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PR Summary

Low Risk
Small refactor that centralizes hint logic; behavior should match prior inlined implementation if the shared helper is equivalent.

Overview
The CoreHint::RandomEcPoint Cairo1 path in the shared hint processor no longer inlines curve sampling and BETA; it delegates to cairo_lang_runner::casm_run::random_ec_point, still driven by get_rng() so OS runs stay deterministic with seeded randomness.

Unused imports are dropped in the aggregator and SNOS hint processors (cell_ref_to_relocatable, Rng where no longer needed).

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[nimrod-starkware]

@nimrod-starkware reviewed 3 files and all commit messages, and made 1 comment.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on ArielElp and yoavGrs).