Add APM retention filter api documentation (#1653)

Co-authored-by: ci.datadog-api-spec <[email protected]>

Author: api-clients-generation-pipeline[bot]

.apigentools-info

@@ -4,13 +4,13 @@
     "spec_versions": {
         "v1": {
             "apigentools_version": "1.6.6",
-            "regenerated": "2023-09-25 12:12:20.967342",
-            "spec_repo_commit": "5d002e79"
+            "regenerated": "2023-09-25 15:28:52.727061",
+            "spec_repo_commit": "a8ef99d8"
         },
         "v2": {
             "apigentools_version": "1.6.6",
-            "regenerated": "2023-09-25 12:12:20.981814",
-            "spec_repo_commit": "5d002e79"
+            "regenerated": "2023-09-25 15:28:52.740393",
+            "spec_repo_commit": "a8ef99d8"
         }
     }
 }