test(deps): update dependency com.google.truth:truth to v1.4.0 (#1537)

* test(deps): update dependency com.google.truth:truth to v1.4.0

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

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Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: renovate-bot