Flaky test in DirectChainSpec

[ch1bo]

Maybe a flaky test: https://github.com/input-output-hk/hydra-poc/runs/6191890966?check_suite_focus=true

 Failures:

  test/Test/DirectChainSpec.hs:236:3: 
  1) Test.DirectChain can restart head to point in the past and replay on-chain events
       uncaught exception: PostTxError
       NoSeedInput

  To rerun use: --match "/Test.DirectChain/can restart head to point in the past and replay on-chain events/"

Randomized with seed 931242145