website: precompress static files instead of relying on fastify compress

- no need to generate the compressed files at runtime
- this prevents an issue with fastify compressing pagefind files

website/package.json

@@ -18,7 +18,6 @@
     "@astrojs/markdown-remark": "^5.1.0",
     "@astrojs/react": "^3.3.1",
     "@astrojs/starlight": "^0.21.5",
-    "@fastify/compress": "^7.0.3",
     "@fastify/static": "^7.0.3",
     "@gouvfr-lasuite/integration": "^0.1.3",
     "@types/prismjs": "^1.26.3",
@@ -26,6 +25,7 @@
     "@types/react-dom": "^18.3.0",
     "@types/react-syntax-highlighter": "^15.5.11",
     "astro": "^4.3.5",
+    "astro-compressor": "^0.4.1",
     "fastify": "^4.26.2",
     "prettier": "^3.2.5",
     "prettier-plugin-astro": "^0.13.0",