Bump polling from 3.3.2 to 3.4.0

Bumps [polling](https://github.com/smol-rs/polling) from 3.3.2 to 3.4.0.
- [Release notes](https://github.com/smol-rs/polling/releases)
- [Changelog](https://github.com/smol-rs/polling/blob/master/CHANGELOG.md)
- [Commits](smol-rs/polling@v3.3.2...v3.4.0)

---
updated-dependencies:
- dependency-name: polling
  dependency-type: indirect
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>