Fix import dev toolbar apps on windows (#9400)

Author: bluwy

.changeset/modern-humans-think.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes importing dev toolbar apps from integrations on Windows

packages/astro/src/vite-plugin-dev-overlay/vite-plugin-dev-overlay.ts

@@ -17,7 +17,7 @@ export default function astroDevOverlay({ settings }: AstroPluginOptions): vite.
 				return `
 					export const loadDevOverlayPlugins = async () => {
 						return [${settings.devToolbarApps
-							.map((plugin) => `(await import('${plugin}')).default`)
+							.map((plugin) => `(await import(${JSON.stringify(plugin)})).default`)
 							.join(',')}];
 					};
 				`;