workspace: upgrade cairo compiler to v2.19.5

[Yoni-Starkware]

Bumps the Rust cairo-lang-* crates and the Sierra compiler binary from 2.19.4 to 2.19.5.

The bump moves the Sierra version from 1.9.3 to 1.9.4 (confirmed against the published cairo-lang-starknet-classes sources), which changes Cairo1 class hashes and cascades into their downstream fixtures.

Version pins

• Cargo.toml: six cairo-lang-* crates -> 2.19.5 (Cargo.lock regenerated)
• crates/apollo_infra_utils/src/cairo_compiler_version.txt -> 2.19.5 (drives the starknet-sierra-compile binary install; cross-checked against Cargo.toml by test_current_compiler_version)
• SierraVersion::LATEST -> 1.9.4

Regenerated fixtures

• starknet_os_flow_tests: fuzz-deployment addresses, hint-coverage JSONs
• proof flow: genesis global root, STRK fee-token address, proof.bin, proof_facts.json
• cende blob regression: operator and fee-token addresses, chain_info.json, preconfirmed_block.json, and blobs re-uploaded to apollo-central-systest-blobs at generation 62

Notable value changes

• Hint coverage gains StatelessHint(EnterScopeNewNode): the changed class hashes reshape the Patricia tree, so traversal now enters a new node where it previously did not.
• Experimental-libfuncs poseidon counts drop 66 -> 64 and 57 -> 55, from compiler output changes in 2.19.5.

🤖 Generated with Claude Code

[cursor]

PR Summary

Medium Risk
Touches Sierra compilation and class hashing used across execution, OS hints, and proof fixtures; wrong pins or stale fixtures would break CI and proof-flow consistency rather than production logic directly.

Overview
Upgrades the workspace Cairo / Sierra toolchain from 2.19.4 to 2.19.5, including the six pinned cairo-lang-* crates in Cargo.toml, regenerated Cargo.lock, and cairo_compiler_version.txt (used for the external starknet-sierra-compile binary).

Sierra 1.9.4 is reflected in SierraVersion::LATEST (was 1.9.3). That changes Cairo1 class hashes and compiled output, so integration fixtures were refreshed: proof-flow genesis global root, STRK fee token address, proof_facts.json, cende blob regression (chain_info.json, preconfirmed_block.json, GCS generation 62), and fuzz deployment address expectations.

OS hint-coverage snapshots now include StatelessHint(EnterScopeNewNode) after Patricia-tree traversal shifts from new class hashes. Poseidon builtin expectations in experimental-libfuncs tests drop slightly (66→64 / 57→55). Cargo.lock also picks up transitive bumps (e.g. hashbrown 0.17.1 for proving-related git deps, socket2 0.6.4).

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[reviewable-StarkWare]

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[einat-starkware]

@einat-starkware reviewed 43 files and made 1 comment.
Reviewable status: all files reviewed (commit messages unreviewed), 1 unresolved discussion (waiting on avi-starkware, matanl-starkware, and Yoni-Starkware).

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-- commits line 4 at r2:
Currently two commits, need to squash them

[Yoni-Starkware]

@Yoni-Starkware made 1 comment.
Reviewable status: all files reviewed (commit messages unreviewed), 1 unresolved discussion (waiting on avi-starkware, einat-starkware, and matanl-starkware).

---

-- commits line 4 at r2:

Previously, einat-starkware wrote…

Currently two commits, need to squash them

Done.

[einat-starkware]

@einat-starkware reviewed all commit messages, made 1 comment, and resolved 1 discussion.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on avi-starkware and matanl-starkware).