refactor(config): remove obsolete quarto netlify.toml

- Remove quarto/netlify.toml (not used in current deployment)
- Current architecture: mlsysbook.ai → Netlify proxy → GitHub Pages
- Root netlify.toml handles proxy configuration with all features
- Quarto version was outdated (wrong PDF path, missing EPUB redirect)

This eliminates confusion about deployment configuration and maintains
single source of truth in root netlify.toml for proxy setup.

quarto/netlify.toml

@@ -1,43 +0,0 @@
-[build]
-  publish = "_book"
-  command = "quarto render --to html"
-
-[[redirects]]
-  from = "/kits"
-  to = "/contents/labs/kits.html"
-  status = 301
-
-[[redirects]]
-  from = "/kits/"
-  to = "/contents/labs/kits.html"
-  status = 301
-
-[[redirects]]
-  from = "/labs"
-  to = "/contents/labs/labs.html"
-  status = 301
-
-[[redirects]]
-  from = "/labs/"
-  to = "/contents/labs/labs.html"
-  status = 301
-
-[[redirects]]
-  from = "/pdf"
-  to = "/assets/Machine-Learning-Systems.pdf"
-  status = 301
-
-# Optional: Add headers for better performance
-[[headers]]
-  for = "/*"
-  [headers.values]
-    X-Frame-Options = "DENY"
-    X-XSS-Protection = "1; mode=block"
-    X-Content-Type-Options = "nosniff"
-    Referrer-Policy = "strict-origin-when-cross-origin"
-
-# Optional: Handle 404s
-[[redirects]]
-  from = "/*"
-  to = "/404.html"
-  status = 404