ci: increase space size and node version for netlify build

netlify.toml

@@ -3,4 +3,5 @@ publish = "docs/.vitepress/dist"
 command = "pnpm run build && pnpm docs:build"
 
 [build.environment]
-NODE_VERSION = "18"
+NODE_VERSION = "20"
+NODE_OPTIONS = '--max-old-space-size=4096'