Revert "[py] ruff fixes in...

Revert "[py] ruff fixes in Tests/Data/ThermoHydroMechanics/Linear/Point_injection/SaturatedPointheatsource.ipynb."

This reverts commit 138138b4.

Pickle fix is required on all platforms but breaks subsequent code in
e.g.

    print(result[0])
    runtimes.append(result[1])