refactor(core): Centralize SSH Tunnel management (#9906)

Co-authored-by: Michael Kret <michael.k@radency.com>

packages/nodes-base/nodes/MySql/v2/methods/credentialTest.ts

@@ -1,25 +1,19 @@
 import type {
-	ICredentialDataDecryptedObject,
 	ICredentialsDecrypted,
 	ICredentialTestFunctions,
 	INodeCredentialTestResult,
 } from 'n8n-workflow';
 
-import { Client } from 'ssh2';
 import { createPool } from '../transport';
+import type { MysqlNodeCredentials } from '../helpers/interfaces';
 
 export async function mysqlConnectionTest(
 	this: ICredentialTestFunctions,
 	credential: ICredentialsDecrypted,
 ): Promise<INodeCredentialTestResult> {
-	const credentials = credential.data as ICredentialDataDecryptedObject;
+	const credentials = credential.data as MysqlNodeCredentials;
 
-	let sshClient: Client | undefined = undefined;
-
-	if (credentials.sshTunnel) {
-		sshClient = new Client();
-	}
-	const pool = await createPool(credentials, {}, sshClient);
+	const pool = await createPool.call(this, credentials);
 
 	try {
 		const connection = await pool.getConnection();
@@ -30,9 +24,6 @@ export async function mysqlConnectionTest(
 			message: error.message,
 		};
 	} finally {
-		if (sshClient) {
-			sshClient.end();
-		}
 		await pool.end();
 	}