No, you will not lose your backup jobs if you upgrade to the latest version. Here is what happens after an upgrade:
If you have the same major version and you update to a minor version (i.e. updating from 9.1 to 9.3) your backup jobs and configurations will be preserved.
If you have an older major version and you upgrade to the latest major version (i.e. upgrading form 8.x to 9.x), the new version will be installed separately. You will have to import your backup jobs and configurations from the previous version.