Bump chess-openings from 374db4b to e6b3f15

Bumps [chess-openings](https://github.com/lichess-org/chess-openings) from `374db4b` to `e6b3f15`.
- [Commits](lichess-org/chess-openings@374db4b...e6b3f15)

---
updated-dependencies:
- dependency-name: chess-openings
  dependency-type: direct:production
...

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