Update Rust crate async-std to 1.12.0

Author: renovate[bot]

async-vfs-os/Cargo.toml

@@ -14,7 +14,7 @@ readme = "README.md"
 async-vfs = { path = "../async-vfs", version = "^0.56.0" }
 cfg-if = "1.0.0"
 futures-lite = "1.12.0"
-async-std = { version = "1.6.0", features = [ "attributes" ], optional = true }
+async-std = { version = "1.12.0", features = [ "attributes" ], optional = true }
 smol = { version = "1.2.5", optional = true }
 smol-potat = { version = "1.1.2", optional = true }
 tokio = { version = "1.13.0", optional = true, features = ["full", "test-util"] }