fix(prefetch): optimise prefetch script (#15874)

Co-authored-by: astrobot-houston <fred+astrobot@astro.build>

Author: ematipico

.changeset/swift-terms-lose.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes a warning when using `prefetchAll`

packages/astro/src/vite-plugin-environment/index.ts

@@ -90,7 +90,7 @@ export function vitePluginEnvironment({
 						// For the dev toolbar
 						'astro > html-escaper',
 					],
-					exclude: ['astro:*', 'virtual:astro:*'],
+					exclude: ['astro:*', 'virtual:astro:*', 'astro/virtual-modules/prefetch.js'],
 					// Astro files can't be rendered on the client
 					entries: [`${srcDirPattern}**/*.{jsx,tsx,vue,svelte,html}`],
 				};