chore: upgrade rust toolchain to 1.90

[hanabi1224]

Summary of changes

Changes introduced in this pull request:

• upgrade rust toolchain to 1.90
• fix new clippy warnings

Reference issue to close (if applicable)

Closes

Other information and links

Change checklist

• I have performed a self-review of my own code,
• I have made corresponding changes to the documentation. All new code adheres to the team's documentation standards,
• I have added tests that prove my fix is effective or that my feature works (if possible),
• I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.

Summary by CodeRabbit

• New Features
  • No user-facing features added.
• Refactor
  • Streamlined and reduced public API surface by removing unused/deprecated types and re-exports.
  • Consolidated serialization helpers and simplified internal readers.
  • Standardized numeric checks for periodic logging and progress reporting.
• Tests
  • Cleaned up test-only structures and imports.
• Chores
  • Upgraded Rust toolchain to 1.90.0.

No functional changes expected for end-users.

[coderabbitai]

Walkthrough

Updates Rust toolchain to 1.90.0. Removes several public types and re-exports across auth, beacon tests, chain store, libp2p, lotus_json, RPC types, and ETH types. Adjusts some logging/modulo checks to use is_multiple_of. Adds #[allow(dead_code)] in selector. Minor signature tweak in CAR reader.

Changes

Cohort / File(s)	Summary of Changes
Toolchain bump rust-toolchain.toml	Channel updated from "1.89.0" to "1.90.0"; components unchanged.
Auth API surface src/auth/mod.rs	Removed public Error enum (variants: MethodParam, InvalidPermissions, NoAuthHeader, Other). No replacement type added.
Beacon test type removal src/beacon/tests/drand.rs	Removed public BeaconEntryJson struct and related serde imports; tests otherwise unchanged.
Chain headchange JSON removal src/chain/store/chain_store.rs	Removed mod headchange_json, public HeadChangeJson enum, and From<HeadChange> impl. Core HeadChange unaffected.
DB CAR updates src/db/car/forest/index/hash.rs, src/db/car/plain.rs	Replaced (a % b == 0) with a.is_multiple_of(b) in div_ceil. Removed public CompressedBlockDataLocation; adjusted read_block_data_location_and_skip to accept impl Read + Seek directly (not a tuple).
Selector annotations src/ipld/selector/mod.rs	Added #[allow(dead_code)] to several types; no public signatures changed.
Libp2p re-export removal src/libp2p/mod.rs	Removed pub use cid::multihash::Multihash;.
Lotus JSON miner params src/lotus_json/actors/params/miner_params.rs	Removed public ExtendSectorExpirationParams type.
ETH subscription types src/rpc/methods/eth/types.rs	Removed public SubscriptionID type and lotus_json helper; associated derives removed.
RPC types consolidation src/rpc/types/mod.rs	Removed public PeerID, ApiState, ApiDecodedParams and related lotus_json helpers; removed libp2p::Multihash usage.
Progress/logging predicate updates src/rpc/methods/state.rs, src/state_migration/common/state_migration.rs	Replaced modulo-based periodic checks with is_multiple_of(...); behavior equivalent.

Sequence Diagram(s)

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• chore: remove serde_tuple in favor of fvm_ipld_encoding::tuple #5906 — Similar refactors around serialization imports and tuple handling; likely adjacent to API/type surface cleanups seen here.

Suggested labels

rust

Suggested reviewers

• LesnyRumcajs
• sudo-shashank
• elmattic

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title Check	✅ Passed	The title concisely and accurately captures the primary change—upgrading the Rust toolchain to version 1.90—as stated in the PR objectives, without unnecessary detail or ambiguity.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch hm/rust-1.90

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