Make the pre-push script work on directories with spaces

As a secondary benefit, it's also a lot simpler.

Author: jyn514

src/etc/pre-push.sh

@@ -10,16 +10,8 @@ set -Eeuo pipefail
 # https://github.com/rust-lang/rust/issues/77620#issuecomment-705144570
 unset GIT_DIR
 ROOT_DIR="$(git rev-parse --show-toplevel)"
-COMMAND="$ROOT_DIR/x.py test tidy"
 
-if [[ "$OSTYPE" == "msys" || "$OSTYPE" == "win32" ]]; then
-  COMMAND="python $COMMAND"
-elif ! command -v python &> /dev/null; then
-  COMMAND="python3 $COMMAND"
-fi
-
-echo "Running pre-push script '$COMMAND'"
+echo "Running pre-push script $ROOT_DIR/x test tidy"
 
 cd "$ROOT_DIR"
-
-$COMMAND
+./x test tidy