chore(deps): bump rust to nightly-2026-07-01

[vladb-ai]

Replicated from alpenlabs#176

Description

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature/Enhancement (non-breaking change which adds functionality or enhances an existing one)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactor
• New or updated tests
• Dependency update
• Security fix

Notes to Reviewers

Checklist

• I have performed a self-review of my code.
• I have commented my code where necessary.
• I have updated the documentation if needed.
• My changes do not introduce new warnings.
• I have added tests that prove my changes are effective or that my feature works.
• New and existing tests pass with my changes.

Related Issues

[github-actions]

🔒 AI Security Review

Reviewed the diff (gh pr diff 1) and the surrounding code in crates/test-utils/btc/src/lib.rs.

Summary of changes: toolchain bump (nightly-2026-06-01 → nightly-2026-07-01), an import re-order (rustfmt grouping), and a swap of chunks_exact(Header::SIZE) for as_chunks::<{ Header::SIZE }>().0 when iterating over a bundled Bitcoin header fixture.

Findings: none.

• Both edits are confined to a test-utilities crate that only deserializes fixture data pulled in via include_bytes! at compile time — there is no network, user, or otherwise untrusted input on this path.
• as_chunks and chunks_exact are behaviorally equivalent for this call site: both yield fixed-size, non-overlapping chunks and ignore any trailing remainder. The remainder is guaranteed empty here since the caller already asserts raw_headers.len() % Header::SIZE == 0 immediately above the loop, so there's no change in parsed output or panic behavior.
• No injection, deserialization-of-untrusted-data, authn/authz, cryptographic, memory-safety, integer-overflow, or DoS concerns are introduced or exposed by this diff.

No action needed from a security standpoint.