Make only live website indexable

This change updates how we run Hugo AND changes the logic for checking
whether a page should be indexable (copied with a backport from upstream
Docsy).

netlify.toml

@@ -20,17 +20,10 @@ HUGO_ENABLEGITINFO = "true"
 command = "git submodule update --init --recursive --depth 1 && make deploy-preview"
 
 [context.branch-deploy]
-command = "git submodule update --init --recursive --depth 1 && make deploy-preview"
+command = "git submodule update --init --recursive --depth 1 && make non-production-build"
 
-[context.master]
-# This context is triggered by the `master` branch and allows search indexing
+[context.main]
+# This context is triggered by the `main` branch and allows search indexing
 # DO NOT REMOVE THIS (contact @kubernetes/sig-docs-leads)
 publish = "public"
 command = "git submodule update --init --recursive --depth 1 && make production-build"
-
-# adding in headers to prevent clickjacking
-[[headers]]
-  for = "/*"
-  [headers.values]
-    X-Frame-Options = "DENY"
-    X-XSS-Protection = "1; mode=block"