chore: satisfy Rust 1.97 useless_borrows_in_formatting lint

[shane-moore]

Problem, Evidence, and Context

• CI's check-code job runs make lint against the latest stable Rust, which is now 1.97 (released 2026-07-07). Rust 1.97 tightened clippy::useless_borrows_in_formatting, which now fires on two pre-existing redundant references passed to write!/format! macros.
• Because the offending lines live on unstable, check-code is currently red on every open PR (e.g. feat: instruments proposer QBFT lifecycle #1105), not any single feature branch.
• Evidence: cargo clippy --workspace --tests under 1.97 fails with redundant reference in write!/format! argument at logging/src/format.rs:204 and eth/src/sync.rs:166.

Change Overview

• Drop the redundant & in two format-macro arguments:
  • logging/src/format.rs span-fields formatter
  • eth/src/sync.rs WS-bind error message
• No behavior change; purely satisfies the stricter lint. Nothing else was touched (Cargo.lock unchanged).

Risks, Trade-offs, and Mitigations

• None of note. Display output is identical whether the value is borrowed or not; the & was always redundant.

Validation

• make lint (clippy under Rust 1.97) passes clean across the full workspace after the change.
• cargo fmt --check passes.

Rollback

• Revert the commit; no config, data, or runtime impact.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 62.63%. Comparing base (7266189) to head (84d9950).

Files with missing lines	Patch %	Lines
anchor/eth/src/sync.rs	0.00%	1 Missing ⚠️
anchor/logging/src/format.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##           unstable    #1127   +/-   ##
=========================================
  Coverage     62.62%   62.63%           
=========================================
  Files           161      161           
  Lines         26925    26922    -3     
=========================================
  Hits          16862    16862           
+ Misses        10063    10060    -3     

Flag	Coverage Δ
rust	62.63% <0.00%> (+<0.01%)	⬆️

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