Hydra-plutus tests are actually red and golden tests got side-stepped

[ch1bo]

Context & versions

On current master cb5a8c8, we have a green CI https://github.com/input-output-hk/hydra/actions/runs/9280096242.

BUT, the hydra-plutus tests are actually RED.

Steps to reproduce

1. Checkout cb5a8c8e9ed0af7a2f8ba422ab78f042d4ee4920
2. cd hydra-plutus
3. cabal run hydra-plutus:exe:tests

This is related to #1449 as to verify this, you need to run the tests in the right directory. And a false sense of security is created by seeing the tests green (although they generated new golden files).

Actual behavior

Our CI allowed a change to hydra-plutus to be merged to master without

• forcing to regenerate golden files
• encouraging a CHANGELOG entry that captures this, leading to downstream surprise of Hydra explorer not showing any heads #1457

Expected behavior

The CI to actually run the hydra-plutus tests, detect breaking changes by seeing golden tests red (and their intended consequence of documenting detected breaking changes)

Hypothesis

• This Github action run should have caught this https://github.com/input-output-hk/hydra/actions/runs/9256084766/job/25461316118
• But the nix build .#checks.x86_64-linux.hydra-plutus seemingly does not run the hydra-plutus tests.

[locallycompact]

#1459

[ch1bo]

Fixed by #1459