For reach release of Laravel the advice is to upgrade the 3rd party packages. For example, this is from the release notes for Laravel 6:
Next, examine any 3rd party packages consumed by your application and verify you are using the proper version for Laravel 6 support.
How do I know which is the "proper version for Laravel 6 support"?
When I check the Packagist entries for components listed in composer.json
it usually states which PHP versions it is compatible with, and lists its own dependencies, but there is rarely (if ever) any mention of compatible Laravel versions.