DOC: drop manual 0_dataset.md entry per microsoft#1707

@romanlutz pointed out the manual entry in 0_dataset.md is a small
hardcoded subset; the canonical list is generated by re-executing
1_loading_datasets.ipynb (which his microsoft#1707 handles). Dropping the
manual line; auto-registration via SeedDatasetProvider already
ensures agent_threat_rules appears in the regenerated notebook
output once microsoft#1707 lands.

Author: eeee2345

doc/code/datasets/0_dataset.md

@@ -53,6 +53,5 @@ A `SeedDataset` is a collection of related `SeedGroups` that you want to test to
 - `harmbench`: Standard harmful behavior benchmarks
 - `dark_bench`: Dark pattern detection examples
 - `airt_*`: Various harm categories from AI Red Team
-- `agent_threat_rules`: Agent Threat Rules (ATR) adversarial payloads for prompt injection, tool poisoning, and other AI-agent attack classes
 
 Datasets can be loaded from local YAML files or fetched remotely from sources like HuggingFace, making it easy to share and version test cases across teams.