Fix concatenating epochs cropped after baseline correction

[kalomak]

Reference issue (if any)

Fixes #12153.

What does this implement/fix?

Fixes concatenate_epochs failing on epochs cropped after baseline correction.

Before this change, concatenation passed the original baseline to the EpochsArray constructor. The constructor rejected it because the baseline period was outside the cropped time range.

This uses the same approach as _evoked_from_epoch_data(): construct the result without baseline correction, then restore the original baseline metadata.

out = EpochsArray(..., baseline=None)
out.baseline = baseline

This means that mne.concatenate_epochs does not apply baseline correction when creating the new EpochsArray. Pending baseline corrections are already applied when the input epoch data are loaded earlier in the function.

[larsoner]

Looks reasonable, thanks @kalomak !