Bump github.com/theupdateframework/go-tuf from 0.3.0 to 0.3.1 (#906)

* Bump github.com/theupdateframework/go-tuf from 0.3.0 to 0.3.1

Bumps [github.com/theupdateframework/go-tuf](https://github.com/theupdateframework/go-tuf) from 0.3.0 to 0.3.1.
- [Release notes](https://github.com/theupdateframework/go-tuf/releases)
- [Commits](https://github.com/theupdateframework/go-tuf/compare/v0.3.0...v0.3.1

)

---
updated-dependencies:
- dependency-name: github.com/theupdateframework/go-tuf
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

* update error

Signed-off-by: Asra Ali <asraa@google.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Asra Ali <asraa@google.com>