fix(deps): update dependency astro to v6

Author: renovate[bot]

demo-app/package.json

@@ -10,7 +10,7 @@
     "preview": "astro preview"
   },
   "dependencies": {
-    "astro": "^5.18.0",
+    "astro": "^6.0.0",
     "lqip-modern": "^2.2.1",
     "sqip": "^1.0.0-beta.1",
 

integrations/__tests__/fixtures/astro-app/package.json

@@ -6,7 +6,7 @@
     "build": "astro build"
   },
   "dependencies": {
-    "astro": "^5.0.0",
+    "astro": "^6.0.0",
     "vite-plugin-sqip": "file:../../../vite-plugin-sqip",
     "sqip": "file:../../../../packages/sqip",
     "sqip-plugin-primitive": "file:../../../../packages/sqip-plugin-primitive",