Bump vividus-build-system from ff959fa to 6c81fab (#5132)

Bumps [vividus-build-system](https://github.com/vividus-framework/vividus-build-system) from `ff959fa` to `6c81fab`.
- [Commits](vividus-framework/vividus-build-system@ff959fa...6c81fab)

---
updated-dependencies:
- dependency-name: vividus-build-system
  dependency-type: direct:production
...

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