Update embedded-hal-async requirement

Updates the requirements on [embedded-hal-async](https://github.com/rust-embedded/embedded-hal) to permit the latest version.
- [Release notes](https://github.com/rust-embedded/embedded-hal/releases)
- [Commits](rust-embedded/embedded-hal@embedded-hal-async-v0.2.0-alpha.1...embedded-hal-async-v0.2.0-alpha.1)

---
updated-dependencies:
- dependency-name: embedded-hal-async
  dependency-type: direct:production
...

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

Cargo.toml

@@ -33,7 +33,7 @@ default = ["eh0", "embedded-time"]
 eh0 = { package = "embedded-hal", version = "0.2.7", features = ["unproven"], optional = true }
 eh1 = { package = "embedded-hal", version = "=1.0.0-alpha.10", optional = true }
 embedded-hal-nb = { version = "=1.0.0-alpha.2", optional = true }
-embedded-hal-async = { version = "=0.2.0-alpha.1", optional = true }
+embedded-hal-async = { version = "=0.2.0-alpha.2", optional = true }
 embedded-time = { version = "0.12", optional = true }
 nb = { version = "0.1.1", optional = true}
 void = { version = "^1.0", optional = true }