Bump spec_tests/hed-specification from a659865 to 2e84bec

Bumps [spec_tests/hed-specification](https://github.com/hed-standard/hed-specification) from `a659865` to `2e84bec`.
- [Release notes](https://github.com/hed-standard/hed-specification/releases)
- [Commits](hed-standard/hed-specification@a659865...2e84bec)

---
updated-dependencies:
- dependency-name: spec_tests/hed-specification
  dependency-type: direct:production
...

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