Bump paper_trail from 7.1.2 to 7.1.3 in /backend
Bump paper_trail from 7.1.2 to 7.1.3 in /backend

Bumps [paper_trail](https://github.com/airblade/paper_trail) from 7.1.2 to 7.1.3.
- [Changelog](https://github.com/airblade/paper_trail/blob/master/CHANGELOG.md)
- [Commits](https://github.com/airblade/paper_trail/compare/v7.1.2...v7.1.3)
roschaefer/rundfunk-mitbestimmen,roschaefer/rundfunk-mitbestimmen,roschaefer/rundfunk-mitbestimmen