fix: Make file route HMR work on Windows (#2978) (CP: 24.5) (#2981)

Fixes #2964

Author: vaadin-bot

packages/ts/file-router/src/vite-plugin.ts

@@ -115,7 +115,8 @@ export default function vitePluginFileSystemRouter({
     },
     transform(code, id): Promise<TransformResult> | TransformResult {
       let modifiedCode = code;
-      if (id.startsWith(fileURLToPath(_viewsDir)) && !basename(id).startsWith('_')) {
+      const viewsDirUsingSlashes = fileURLToPath(_viewsDir).replaceAll('\\', '/');
+      if (id.startsWith(viewsDirUsingSlashes) && !basename(id).startsWith('_')) {
         if (isDevMode) {
           // To enable HMR for route files with exported configurations, we need
           // to address a limitation in `react-refresh`. This library requires