Change preprocessing parameters

[amyxli]

We want to apply a bandpass filter of 0.25-40hz, and check the other settings (e.g., bad_segments significance levels) again to ensure that they are appropriate.

[cedricfoucault]

@amyxli Along with this change, we should remove the second temporal filtering that was performed in the source reconstruction script, as it is redundant with the one done during preprocessing.

The logic is the following:

• Temporal filtering that is not analysis-dependent should be handled at the preprocessing stage.
• Any further filtering that is analysis-dependent should be performed by the analysis script for the analyses that require it.