Update pull-requests.json from main (#39547)

This commit updates the pull-requests.json file for the BK PR Bot from
main. It's not consulted in any way, but it reduces conflicts with
backports that include it.

.buildkite/pull-requests.json

@@ -5,17 +5,13 @@
             "pipelineSlug": "beats",
             "allow_org_users": true,
             "allowed_repo_permissions": ["admin", "write"],
-<<<<<<< HEAD
-            "allowed_list": [ ],
-=======
             "allowed_list": ["dependabot[bot]", "mergify[bot]"],
->>>>>>> a992601dac (Allow dependabot report BK status checks (#39540))
             "set_commit_status": true,
             "build_on_commit": true,
             "build_on_comment": true,
-            "trigger_comment_regex": "^/test .*$",
-            "always_trigger_comment_regex": "^/test .*$",
-            "skip_ci_labels": [ ],
+            "trigger_comment_regex": "^/(?:test)",
+            "always_trigger_comment_regex": "^/(?:test)",
+            "skip_ci_labels": ["skip-ci"],
             "skip_target_branches": [ ],
             "skip_ci_on_only_changed": [ ],
             "always_require_ci_on_changed": [ ]