chore(deps): patch Rustls advisories and quiet known duplicates

[benbrandt]

Summary

• Update the locked Rustls dependency from 0.23.45 to 0.23.46, fixing RUSTSEC-2026-0346, RUSTSEC-2026-0347, RUSTSEC-2026-0348, and RUSTSEC-2026-0349.
• Add 13 documented, exact-version cargo-deny exceptions for known duplicate dependencies imposed by upstream version requirements.
• Keep duplicate-version warnings enabled and security advisory checks unchanged. These exceptions do not automatically cover future dependency versions.

Resolves the security audit failure in https://github.com/agentclientprotocol/rust-sdk/actions/runs/38887121377/job/116927450715?pr=423.

Validation

• Reproduced all four advisory failures before the Rustls update.
• cargo deny --all-features check passes with no warnings after both changes.
• git diff --check passes.
• just test was started but interrupted during the preparation build; the full test suite has not completed locally.
• Maintainer reported cargo outdated --workspace -R found no outdated dependencies (with an additional "Update for yopo could not be found!" message).