Calling make_complete() on an instance of MultiIndexSet raises an exception

Following MR !64 (merged) (see Issue #37 (closed)), the default constructor of the MultiIndexSet class now explicitly requires the value of lp_degree to be passed because it cannot be inferred just from a given set of exponents.

However, it appears some part of the codebase still assume that lp_degree in the default constructor has a default value. Specifically, in the make_complete() method (line 361):

...
new_instance = self.__class__(new_exponents)  # re-compute degree etc.
...

Calling make_complete() on an instance of MultiIndexSet raises an exception:

>>> mi = mp.MultiIndexSet(np.array([[0, 0, 2]]), lp_degree=2.0)
>>> mi.make_complete()
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[7], line 1
----> 1 mi.make_complete()

File ~/projects/minterpy/dev-113/src/minterpy/core/multi_index.py:361, in MultiIndexSet.make_complete(self)
    359     return self
    360 new_exponents = self.exponents_completed  # compute if necessary!
--> 361 new_instance = self.__class__(new_exponents)  # re-compute degree etc.
    362 # NOTE: avoid checking for completeness again!
    363 new_instance._is_complete = True

TypeError: __init__() missing 1 required positional argument: 'lp_degree'

It also seems there is no tests yet for make_complete() method, otherwise this problem would have been caught during the merge request (see MR !64 (merged)).

PS: I'm assigning this to myself. The MR related to this Issue is a (very) small hotfix and I will merge them immediately so as not to obstruct other developments.