Remove Deprecated APIs for Version 25.06

[csadorf]

Several APIs were deprecated in version 25.04 and are scheduled for removal in version 25.06.

• Remove convert_dtype and handle parameters from accuracy_score function in python/cuml/cuml/metrics/_classification.py
• Remove multiclass_strategy parameter from SVC class in python/cuml/cuml/svm/svc.pyx

[csadorf]

@jcrist Would appreciate if you could also do a quick search of the code base in case that I missed any others (likely).

[jcrist]

I did and handled all but the FIL ones in #6754. Haven't checked, but assumed the FIL ones were being handled in the already up FIL PRs.