Add shebang to backup command script in utils.ts

- Introduced a shebang line to the backup command script for improved compatibility and execution in a bash environment.
- This change enhances the script's portability and ensures it runs correctly in various shell contexts.

packages/server/src/utils/backups/utils.ts

@@ -220,6 +220,7 @@ export const getBackupCommand = (
 	const containerSearch = getContainerSearchCommand(backup);
 	const backupCommand = generateBackupCommand(backup);
 	return `
+	#!/bin/bash
 	set -eo pipefail;
 	echo "[$(date)] Starting backup process..." >> ${logPath};
 	echo "[$(date)] Executing backup command..." >> ${logPath};