Makes the AstroCookies type importable directly from "astro" (#6006)

* re-exports the AstroCookie type from the main 'astro' types

* chore: add changeset

.changeset/modern-colts-fix.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Makes the `AstroCookies` type available as an import from the main "astro" package

packages/astro/src/@types/astro.ts

@@ -28,6 +28,7 @@ export type {
 	ShikiConfig,
 } from '@astrojs/markdown-remark';
 export type { SSRManifest } from '../core/app/types';
+export type { AstroCookies } from '../core/cookies';
 
 export interface AstroBuiltinProps {
 	'client:load'?: boolean;