fix(core): Ensure pruning starts only after migrations have completed (#7626)

https://linear.app/n8n/issue/PAY-986/bug-execution-pruning-timer-is-started-before-the-database-is-ready

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Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>

packages/cli/src/services/pruning.service.ts

@@ -56,6 +56,9 @@ export class PruningService {
 		return true;
 	}
 
+	/**
+	 * @important Call only after DB connection is established and migrations have completed.
+	 */
 	startPruning() {
 		this.setSoftDeletionInterval();
 		this.scheduleHardDeletion();