pg_dump and pg_restore are the commonly used PostgreSQL tools used for this.
In the project manager, you can expose the database pane to the left if not already visible. the top row in this pane has buttons that can backup and restore selected databases.
Before updating to v17, start up Resolve, select a database. Hover over each button to see what the tooltip says. Click Backup. Select a file location to create a backup copy.
You can update to v17, which will ask you to upgrade the database. Upgrade and continue work.
On the off chance you need to return to v16, you can uninstall 17, reinstall 16.2.8 from the support page. You can then click the Restore button and continue where you left off before updating.