Refactor `filter` and `laterality` modules: `joblib` is not optional

[jhlegarreta]

The filter and laterality modules try to use joblib modules conditionally if importing it is successful:

whitematteranalysis/whitematteranalysis/filter.py

Line 32 in ac6040f

joblib, have_joblib, _ = optional_package("joblib")

whitematteranalysis/whitematteranalysis/laterality.py

Line 35 in ac6040f

joblib, have_joblib, _ = optional_package("joblib")

However, joblib is a required dependency:,

whitematteranalysis/requirements.txt

Line 1 in ac6040f

joblib>=1.1.0

so the if/else blocks in the above modules are not necessary, e.g. (there are multiple hits):

whitematteranalysis/whitematteranalysis/filter.py

Line 610 in ac6040f

if have_joblib and n_jobs > 0:

whitematteranalysis/whitematteranalysis/laterality.py

Line 167 in ac6040f

if (have_joblib & (self.parallel_jobs > 1)):

Removing the conditional blocks may require some work, as the else blocks seem to contain a more complex/different logic with respect to the counterpart using the parallelization capabilities.