Bump Derivre to 0.3.13 (#379)

Bump the exact Derivre dependency from 0.3.12 to 0.3.13 and refresh
Cargo.lock. This allows JSON schema patterns with redundant nested
anchors, such as `^(^foo$)$|^$`, to compile successfully.

Code changes in [Derivre 0.3.12 to
0.3.13](https://github.com/guidance-ai/derivre/compare/v0.3.12...v0.3.13):

- Fix redundant nested start/end anchors while preserving search
semantics, with a regression test for `^(^foo$)$|^$`
([#26](https://github.com/guidance-ai/derivre/pull/26)).
- Fix new Clippy warnings by simplifying byte arrays and propagating
`None` with `?`, with no behavior change
([#23](https://github.com/guidance-ai/derivre/pull/23)).

Validation: `cargo test --locked -p llguidance --test
test_json_string_format --test test_json_primitives` passed all 975
tests; `git diff --check` passed.