build(deps): bump bytes from 1.3.0 to 1.4.0 (RustCrypto#1234)

Bumps [bytes](https://github.com/tokio-rs/bytes) from 1.3.0 to 1.4.0.
- [Release notes](https://github.com/tokio-rs/bytes/releases)
- [Changelog](https://github.com/tokio-rs/bytes/blob/master/CHANGELOG.md)
- [Commits](tokio-rs/bytes@v1.3.0...v1.4.0)

---
updated-dependencies:
- dependency-name: bytes
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]