chore(deps): update rand to 0.10.2

[VerifiedOrganic]

Summary

• update the locked rand release from 0.10.1 to 0.10.2
• retain the existing resolved rand features and every transitive package version
• keep this maintenance slice lockfile-only and independent of parked aggregate PR chore(deps): update Rust minor and patch group #301

Closes #329
Related: #301

Safety and scope

• The final diff is only Cargo.lock: the rand version/checksum and 12 disambiguated dependency references.
• rand_core remains 0.10.1 and getrandom remains 0.4.2; no unrelated lockfile churn is included.
• The resolved rand feature set is unchanged: alloc, default, std, std_rng, sys_rng, and thread_rng. The serde feature is not enabled.
• The SDK contains no UniformChar, Uniform<char>, or rand-serde use, so this PR does not claim demonstrated exposure to the upstream deserialization defect.
• No public API, runtime configuration, documentation contract, unsafe code, or production dependency manifest changes.

Upstream

• rand 0.10.2 changelog: https://github.com/rust-random/rand/blob/0.10.2/CHANGELOG.md
• upstream UniformChar soundness fix: Check UniformChar validity on deser rust-random/rand#1790

Validation

• cargo test --locked --workspace --exclude opc-persist --all-features --quiet -- --test-threads=4: passed
• cargo test --locked -p opc-persist --all-features --quiet -- --test-threads=1: passed
• cargo clippy --locked --workspace --all-targets --all-features -- -D warnings: passed
• affected-package all-feature test suites: passed
• cargo deny check advisories: passed
• cargo deny check bans licenses sources: passed
• fresh cargo audit --deny warnings: passed
• cargo fmt --all --check: passed
• cargo metadata --locked: passed
• git diff --check: passed
• exact origin/main..HEAD gitleaks scan: passed, zero findings

Checklist

• Commit is GPG-signed and DCO signed-off.
• Diff is lockfile-only and contains no transitive version churn.
• Full local validation is green.
• Full GitHub Actions pass before merge.
• PR chore(deps): update Rust minor and patch group #301 remains parked and unchanged.