Bump h2 from 0.3.24 to 0.3.26 in /tests/hello-rustls

Bumps [h2](https://github.com/hyperium/h2) from 0.3.24 to 0.3.26.
- [Release notes](https://github.com/hyperium/h2/releases)
- [Changelog](https://github.com/hyperium/h2/blob/v0.3.26/CHANGELOG.md)
- [Commits](hyperium/h2@v0.3.24...v0.3.26)

---
updated-dependencies:
- dependency-name: h2
  dependency-type: indirect
...

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