Add anthropic false positives (#1781)

Author: AlteredCoder

taxonomy/false_positives.json

@@ -1,4 +1,9 @@
 {
+    "ai:anthropic": {
+        "description": "IP is used by Anthropic and should not be flagged as a threat.",
+        "label": "Anthropic",
+        "name": "ai:anthropic"
+    },
     "cdn:cloudflare_exit_node": {
         "description": "IP is a Cloudflare CDN exit IP and should not be flagged as a threat.",
         "label": "Cloudflare CDN",