build(deps): update async-task requirement from ^1.3 to ^3.0

Updates the requirements on [async-task](https://github.com/stjepang/async-task) to permit the latest version.
- [Release notes](https://github.com/stjepang/async-task/releases)
- [Changelog](https://github.com/stjepang/async-task/blob/master/CHANGELOG.md)
- [Commits](https://github.com/stjepang/async-task/commits)

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

heim-runtime/Cargo.toml

@@ -18,7 +18,7 @@ futures-util = { version = "^0.3", default-features = false, features = ["std",
 pin-utils = { version = "0.1.0-alpha.4", optional = true }
 
 # runtime-polyfill
-async-task = { version = "^1.3", optional = true }
+async-task = { version = "^3.0", optional = true }
 crossbeam-utils = { version = "~0.7", optional = true }
 futures-channel = "^0.3"
 futures-timer = "~3.0"