contrib: improve check-fmt.sh script

Try to install toolchain only if not exists

Signed-off-by: Yuki Kishimoto <[email protected]>

Author: yukibtc

contrib/scripts/check-fmt.sh

@@ -2,6 +2,7 @@
 
 set -euo pipefail
 
+version="nightly-2024-01-11"
 flags=""
 
 # Check if "check" is passed as an argument
@@ -10,8 +11,7 @@ if [[ "$#" -gt 0 && "$1" == "check" ]]; then
 fi
 
 # Install toolchain
-rustup install nightly-2024-01-11
-rustup component add rustfmt --toolchain nightly-2024-01-11
+cargo +$version --version || (rustup install $version && rustup component add rustfmt --toolchain $version)
 
 # Check workspace crates
-cargo +nightly-2024-01-11 fmt --all -- --config format_code_in_doc_comments=true $flags
+cargo +$version fmt --all -- --config format_code_in_doc_comments=true $flags