build: update npm install command to use --legacy-peer-deps

This change modifies the build scripts to use --legacy-peer-deps flag when installing npm dependencies to resolve potential peer dependency conflicts during the build process. The change is applied to both bash (build.sh) and batch (build.bat) build scripts.

frontend/node_modules/eslint/messages/shared.js

@@ -12,12 +12,7 @@
  * @returns {string} The value, stringified.
  */
 function stringifyValueForError(value, indentation) {
-	return value
-		? JSON.stringify(value, null, 4).replace(
-				/\n/gu,
-				`\n${" ".repeat(indentation)}`,
-			)
-		: `${value}`;
+    return value ? JSON.stringify(value, null, 4).replace(/\n/gu, `\n${" ".repeat(indentation)}`) : `${value}`;
 }
 
 module.exports = { stringifyValueForError };