Numpy deprecation warning for RT tests

[yoricklassmann]

Hi @JanosJiri, I have successfully compiled qdyn, and all tests passed. However, I am seeing that for some of the tests, numpy is complaining:

ABSOLUTE_PATH/qdyn/tests/RT_LaserPulse_CH3I_1D/check_ch3i.py:37: DeprecationWarning: `trapz` is deprecated.
Use `trapezoid` instead, or one of the numerical integration functions in `scipy.integrate`

It would be very easy to update, such that this warning is not written anymore, and the tests still run after numpy removes trapz in the future.

[JanosJiri]

Thanks for letting me know @yoricklassmann, I haven't used the package for a while. I will upgrate the scripts to np.trapezoid as soon as I have some time.

[JanosJiri]

I updated the scripts with np.trapezoid.