chore: exclude some logs-monitor code from coverage (#32107)

Code that *may* or *may not* run should be excluded from coverage.

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: iliapolo

packages/aws-cdk/lib/api/logs/logs-monitor.ts

@@ -125,6 +125,9 @@ export class CloudWatchLogEventMonitor {
 
   private async tick(): Promise<void> {
     if (!this.active) {
+      // excluding from codecoverage because this
+      // doesn't always run (depends on timing)
+      /* istanbul ignore next */
       return;
     }
     try {