Removed unused import and updated the path. (#10894)

* Updated path handling in examples/preprocessing/otp.py

* Removed unused import 'op'

* Remove Paranthesis

Co-authored-by: archit singhal <zyphergiest@pop-os.localdomain>

Author: architsinghal-mriirs

examples/preprocessing/otp.py

@@ -15,7 +15,6 @@
 
 # %%
 
-import os.path as op
 import mne
 import numpy as np
 
@@ -34,8 +33,7 @@
 
 dipole_number = 1
 data_path = bst_phantom_elekta.data_path()
-raw = read_raw_fif(
-    op.join(data_path, 'kojak_all_200nAm_pp_no_chpi_no_ms_raw.fif'))
+raw = read_raw_fif(data_path / 'kojak_all_200nAm_pp_no_chpi_no_ms_raw.fif')
 raw.crop(40., 50.).load_data()
 order = list(range(160, 170))
 raw.copy().filter(0., 40.).plot(order=order, n_channels=10)