build(deps): bump braze-specification from 1d90b6c to 6d2b78c

Bumps [braze-specification](https://github.com/braze-community/braze-specification) from `1d90b6c` to `6d2b78c`.
- [Release notes](https://github.com/braze-community/braze-specification/releases)
- [Commits](braze-community/braze-specification@1d90b6c...6d2b78c)

---
updated-dependencies:
- dependency-name: braze-specification
  dependency-type: direct:production
...

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