Bump h2 from 0.4.11 to 0.4.12 (#846)

Bumps [h2](https://github.com/hyperium/h2) from 0.4.11 to 0.4.12.
- [Release notes](https://github.com/hyperium/h2/releases)
- [Changelog](https://github.com/hyperium/h2/blob/master/CHANGELOG.md)
- [Commits](hyperium/h2@v0.4.11...v0.4.12)

---
updated-dependencies:
- dependency-name: h2
  dependency-version: 0.4.12
  dependency-type: direct:production
  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>

Author: dependabot[bot]