Get rid of unnecessary use of async-std in non-test code (#10891)

substrate/Cargo.lock

@@ -254,23 +254,6 @@ dependencies = [
  "event-listener",
 ]
 
-[[package]]
-name = "async-process"
-version = "1.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b21b63ab5a0db0369deb913540af2892750e42d949faacc7a61495ac418a1692"
-dependencies = [
- "async-io",
- "blocking",
- "cfg-if 1.0.0",
- "event-listener",
- "futures-lite",
- "libc",
- "once_cell",
- "signal-hook",
- "winapi 0.3.9",
-]
-
 [[package]]
 name = "async-std"
 version = "1.10.0"
@@ -282,7 +265,6 @@ dependencies = [
  "async-global-executor",
  "async-io",
  "async-lock",
- "async-process",
  "crossbeam-utils 0.8.5",
  "futures-channel",
  "futures-core",
@@ -9389,16 +9371,6 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42a568c8f2cd051a4d283bd6eb0343ac214c1b0f1ac19f93e1175b2dee38c73d"
 
-[[package]]
-name = "signal-hook"
-version = "0.3.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef33d6d0cd06e0840fba9985aab098c147e67e05cee14d412d3345ed14ff30ac"
-dependencies = [
- "libc",
- "signal-hook-registry",
-]
-
 [[package]]
 name = "signal-hook-registry"
 version = "1.3.0"
@@ -10515,7 +10487,6 @@ dependencies = [
 name = "substrate-prometheus-endpoint"
 version = "0.10.0-dev"
 dependencies = [
- "async-std",
  "futures-util",
  "hyper 0.14.16",
  "log 0.4.14",