Bump flate2 from 1.0.25 to 1.0.26 in /cmd/zfs_object_agent (openzfs#844)

Bumps [flate2](https://github.com/rust-lang/flate2-rs) from 1.0.25 to 1.0.26.
- [Release notes](https://github.com/rust-lang/flate2-rs/releases)
- [Commits](rust-lang/flate2-rs@1.0.25...1.0.26)

---
updated-dependencies:
- dependency-name: flate2
  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>