Bump is-terminal from 0.4.8 to 0.4.9 in /cmd/zfs_object_agent (openzf…

…s#1011)

Bumps [is-terminal](https://github.com/sunfishcode/is-terminal) from 0.4.8 to 0.4.9.
- [Commits](sunfishcode/is-terminal@v0.4.8...v0.4.9)

---
updated-dependencies:
- dependency-name: is-terminal
  dependency-type: indirect
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>