[Observability Alerting][R&D] Implement/verify cancellation for observability rules

[jasonrhodes]

The alerting team (@elastic/kibana-alerting-services) has recently implemented new tools for auto-canceling/timeouts[1][2] for alerting rules. We should (a) become familiar with these new APIs, and (b) determine if we should be adjusting our rule configs or executor logic to take advantage of these new APIs.

• [Alerting] Provide framework services to enable rule executors to short-circuit execution #113462
• [Alerting] Allow rule types to specify custom timeout values #113487
• Add rule cancellation support for metrics threshold and log threshold rule types #122550

Acceptance Criteria

• Implementation tickets are created, if needed, to address cancellation/timeout for existing observability rule types
• In particular, we should look at the Metrics Threshold, Metrics Inventory, and Log Threshold rule types

[mikecote]

cc @elastic/response-ops

[simianhacker]

This has been implemented globally by the Response Ops team 💃