launch: check prerequisites in a pre-launch task

Fixes https://github.com/microsoft/vscode/issues/103708

scripts/code.sh

@@ -24,11 +24,10 @@ function code() {
 		CODE=".build/electron/$NAME"
 	fi
 
-	# Node modules
-	test -d node_modules || yarn
-
-	# Get electron
-	yarn electron
+	# Get electron, compile, built-in extensions
+	if [[ -z "${VSCODE_SKIP_PRELAUNCH}" ]]; then
+		node build/lib/preLaunch.js
+	fi
 
 	# Manage built-in extensions
 	if [[ "$1" == "--builtin" ]]; then
@@ -36,12 +35,6 @@ function code() {
 		return
 	fi
 
-	# Sync built-in extensions
-	node build/lib/builtInExtensions.js
-
-	# Build
-	test -d out || yarn compile
-
 	# Configuration
 	export NODE_ENV=development
 	export VSCODE_DEV=1