Add `gitlab_page_out_of_bounds` to Prometheus metrics

Adds information on a new counter added in https://gitlab.com/gitlab-org/gitlab/merge_requests/22876.

doc/administration/monitoring/prometheus/gitlab_metrics.md

@@ -32,6 +32,7 @@ The following metrics are available:
 | `gitlab_cache_operations_total`                                | Counter   |                   12.2 | Cache operations by controller/action                                                               | controller, action, operation                       |
 | `gitlab_database_transaction_seconds`                          | Histogram |                   12.1 | Time spent in database transactions, in seconds                                                     |                                                     |
 | `gitlab_method_call_duration_seconds`                          | Histogram |                   10.2 | Method calls real duration                                                                          | controller, action, module, method                  |
+| `gitlab_page_out_of_bounds`                                    | Counter   |                   12.8 | Counter for the PageLimiter pagination limit being hit                                              | controller, action, bot                             |
 | `gitlab_rails_queue_duration_seconds`                          | Histogram |                    9.4 | Measures latency between GitLab Workhorse forwarding a request to Rails                             |                                                     |
 | `gitlab_sql_duration_seconds`                                  | Histogram |                   10.2 | SQL execution time, excluding SCHEMA operations and BEGIN / COMMIT                                  |                                                     |
 | `gitlab_transaction_allocated_memory_bytes`                    | Histogram |                   10.2 | Allocated memory for all transactions (gitlab_transaction_* metrics)                                |                                                     |