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/espree/lib/options.js

@@ -19,9 +19,7 @@ const SUPPORTED_VERSIONS = [
     12, // 2021
     13, // 2022
     14, // 2023
-    15, // 2024
-    16, // 2025
-    17 // 2026
+    15 // 2024
 ];
 
 /**
@@ -29,7 +27,7 @@ const SUPPORTED_VERSIONS = [
  * @returns {number} The latest ECMAScript version.
  */
 export function getLatestEcmaVersion() {
-    return SUPPORTED_VERSIONS.at(-1);
+    return SUPPORTED_VERSIONS[SUPPORTED_VERSIONS.length - 1];
 }
 
 /**