chore(deps): bump tokio in /staking-miner-playground (#1010)

Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.35.1 to 1.38.2.
- [Release notes](https://github.com/tokio-rs/tokio/releases)
- [Commits](tokio-rs/tokio@tokio-1.35.1...tokio-1.38.2)

---
updated-dependencies:
- dependency-name: tokio
  dependency-version: 1.38.2
  dependency-type: indirect
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]