chore: remove prepare script (#8713)

Author: benmccann

packages/svelte/package.json

@@ -75,7 +75,6 @@
     "check": "prettier . --cache --plugin-search-dir=. --check",
     "test": "vitest run && echo \"manually check that there are no type errors in test/types by opening the files in there\"",
     "build": "rollup -c && pnpm types",
-    "prepare": "pnpm build",
     "generate:version": "node ./scripts/generate-version.js",
     "dev": "rollup -cw",
     "posttest": "agadoo src/internal/index.js",