Update sharp to 0.33 to fix issue with Alpine Linux

It was impossible for me to use the Astro image service in an Alpine Linux docker container. Even though I would install sharp `0.33.3` in my app, pnpm would download version `0.32.6`, which doesn't work in Alpine Linux container. 

Currently, I have to override the downloaded version in my package.json. For more details see:
- lovell/sharp#4054
- https://discord.com/channels/830184174198718474/1224861729792458803/1224861729792458803

This PR updates the version of the `sharp` dependency to `^0.33` and thus makes Astro compatible with Alpine Linux.

packages/astro/package.json

@@ -178,7 +178,7 @@
     "zod-to-json-schema": "^3.22.4"
   },
   "optionalDependencies": {
-    "sharp": "^0.32.6"
+    "sharp": "^0.33"
   },
   "devDependencies": {
     "@astrojs/check": "^0.5.8",