feat(core): Improve health check (#6205)

* remove unnecesary Db re-initialization

this is from before we added `Db.init` in `WorkflowRunnerProcess`

* feat(core): Improved health check

* make health check not care about DB connections

* close DB connections, and shutdown the timer

packages/cli/src/CredentialsHelper.ts

@@ -453,12 +453,6 @@ export class CredentialsHelper extends ICredentialsHelper {
 	): Promise<void> {
 		const credentials = await this.getCredentials(nodeCredentials, type);
 
-		if (!Db.isInitialized) {
-			// The first time executeWorkflow gets called the Database has
-			// to get initialized first
-			await Db.init();
-		}
-
 		credentials.setData(data, this.encryptionKey);
 		const newCredentialsData = credentials.getDataToSave() as ICredentialsDb;