Remove broken rescue fallback in prefetch

The rescue block claimed to fall back to per-test caching, but those
cache calls were removed from the test. A silent catch here would let
every subsequent API call hit the network uncached, likely causing
rate-limit failures. Let errors propagate so tests fail fast with a
clear reason.

Author: kenyonj

test/collections_test_helper.rb

@@ -140,26 +140,21 @@ def prefetch_all_collection_items!
   all_repos.uniq!
   all_users.uniq!
 
-  begin
-    # Batch repos in chunks to stay within GraphQL query limits
-    all_repos.each_slice(GRAPHQL_BATCH_SIZE) do |batch|
-      cache_repos_exist_check!(batch)
-    end
-
-    # Batch users in chunks
-    all_users.each_slice(GRAPHQL_BATCH_SIZE) do |batch|
-      cache_users_exist_check!(batch)
-    end
+  # Batch repos in chunks to stay within GraphQL query limits
+  all_repos.each_slice(GRAPHQL_BATCH_SIZE) do |batch|
+    cache_repos_exist_check!(batch)
+  end
 
-    # Check orgs for users not found
-    not_found_users = users_not_found_from(all_users)
-    not_found_users.each_slice(GRAPHQL_BATCH_SIZE) do |batch|
-      cache_orgs_exist_check!(batch)
-    end
+  # Batch users in chunks
+  all_users.each_slice(GRAPHQL_BATCH_SIZE) do |batch|
+    cache_users_exist_check!(batch)
+  end
 
-    # Only mark as done after ALL batch calls completed successfully
-    NewOctokit.global_prefetch_done!
-  rescue StandardError => error
-    warn "Global prefetch failed, falling back to per-test caching: #{error.message}"
+  # Check orgs for users not found
+  not_found_users = users_not_found_from(all_users)
+  not_found_users.each_slice(GRAPHQL_BATCH_SIZE) do |batch|
+    cache_orgs_exist_check!(batch)
   end
+
+  NewOctokit.global_prefetch_done!
 end