Bump dspy from cba4a72 to c6429e4

Bumps [dspy](https://github.com/stanfordnlp/dspy) from `cba4a72` to `c6429e4`.
- [Release notes](https://github.com/stanfordnlp/dspy/releases)
- [Commits](stanfordnlp/dspy@cba4a72...c6429e4)

---
updated-dependencies:
- dependency-name: dspy
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>