bump nimbus-build-system to always bundle checksums #17879

All 4 879 tests pass, 348 skipped in 55m 8s

      12 files   1 810 suites 55m 8s ⏱️
  5 227 tests   4 879 ✔️ 348 💤 0 ❌
29 057 runs 28 605 ✔️ 452 💤 0 ❌

Results for commit 78e87a2.