Persist multiple trees in a single db table, preserving child order

Changes for 1.16 - 2023-07-24T09:43:00Z

• Patch t/Tree/008_weak_refs.t to remove the 2nd paramater in the call to use_ok(). This issue was found by CPAN testers using a recent Perl and reported by Graham Knop, who kindly supplied a patch.