Bump tokio from 1.6.0 to 1.6.1 in /cmd/pinniped-proxy (#2911)

Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.6.0 to 1.6.1.
- [Release notes](https://github.com/tokio-rs/tokio/releases)
- [Commits](tokio-rs/tokio@tokio-1.6.0...tokio-1.6.1)

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

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