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/eslintrc/lib/config-array/extracted-config.js

@@ -120,10 +120,10 @@ class ExtractedConfig {
      */
     toCompatibleObjectAsConfigFileContent() {
         const {
-            /* eslint-disable no-unused-vars -- needed to make `config` correct */
+            /* eslint-disable no-unused-vars */
             configNameOfNoInlineConfig: _ignore1,
             processor: _ignore2,
-            /* eslint-enable no-unused-vars -- needed to make `config` correct */
+            /* eslint-enable no-unused-vars */
             ignores,
             ...config
         } = this;