Bump accountable-refcell from 0.2.0 to 0.2.1

Bumps [accountable-refcell](https://github.com/jdm/accountable-refcell) from 0.2.0 to 0.2.1.
- [Release notes](https://github.com/jdm/accountable-refcell/releases)
- [Commits](jdm/accountable-refcell@v0.2.0...v0.2.1)

---
updated-dependencies:
- dependency-name: accountable-refcell
  dependency-type: indirect
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>