chore(deps): bump serde, thiserror and chrono

[bahdotsh]

Lockfile-only patch bumps, combined into one PR so the third-party notices are regenerated once:

• serde 1.0.228 -> 1.0.229 (chore(deps): bump serde from 1.0.228 to 1.0.229 #413)
• thiserror 2.0.17 -> 2.0.20 (chore(deps): bump thiserror from 2.0.17 to 2.0.20 #415)
• chrono 0.4.42 -> 0.4.45 (chore(deps): bump chrono from 0.4.42 to 0.4.45 #250)

Each Dependabot PR failed only Third-Party Notices Drift, because none of them regenerated the notices files. This PR includes the regenerated THIRD-PARTY-NOTICES.md files (cargo-about 0.9.1, the version the script pins).

The mesh_forwarding failures on #415 and #433 are the known everyone_hearing_everyone_does_not_multiply_the_traffic flake. They are unrelated to these bumps.

Verified locally:

• cargo clippy --workspace -- -D warnings
• no_std clippy on thumbv8m for core, sealed and leaf (serde and thiserror are used there)
• cargo test --workspace: 3024 passed, 0 failed

Dependabot closes #413, #415 and #250 on its own once this lands.