chore: improve score corruption error message

[triceo]

No description provided.

[Christopher-Chianelli]

Test failing; cannot infer type of a variable in a test.

[Christopher-Chianelli]

timefold-solver-benchmarks/src/main/java/ai/timefold/solver/benchmarks/micro/scoredirector/problems/AbstractProblem.java:[111,22] cannot infer type arguments for ai.timefold.solver.core.impl.localsearch.scope.LocalSearchPhaseScope<>
  reason: cannot infer type-variable(s) Solution_
    (actual and formal argument lists differ in length)

[triceo]

The problem comes from the CI, not from the build. (CI checks out the wrong branch.)
Merging.