Update smol requirement from 1.0 to 2.0

Updates the requirements on [smol](https://github.com/smol-rs/smol) to permit the latest version.
- [Release notes](https://github.com/smol-rs/smol/releases)
- [Changelog](https://github.com/smol-rs/smol/blob/master/CHANGELOG.md)
- [Commits](smol-rs/smol@v1.0.0...v2.0.0)

---
updated-dependencies:
- dependency-name: smol
  dependency-type: direct:production
...

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

Cargo.toml

@@ -39,5 +39,5 @@ lazy_static = "1"
 once_cell = "1.14"
 rustls-pemfile = "1"
 rustls-webpki = "0.101"
-smol = "1.0"
+smol = "2.0"
 webpki-roots = "0.25"

examples/client/Cargo.toml

@@ -10,5 +10,5 @@ argh = "0.1"
 async-rustls = { path = "../.." }
 rustls-pemfile = "1"
 rustls-webpki = "0.101"
-smol = "1"
+smol = "2"
 webpki-roots = "0.25"

examples/server/Cargo.toml

@@ -9,4 +9,4 @@ publish = false
 argh = "0.1"
 async-rustls = { path = "../.." }
 rustls-pemfile = "1"
-smol = "1"
+smol = "2"