wave: Deprecate getmark(), setmark() and getmarkers() methods

[vstinner]

The wave module has getmark(), setmark() and getmarkers() methods (in Wave_read and Wave_write classes) which only exist for compatibility with the aifc module which has been removed in Python 3.13 (PR #104933). I propose to remove these methods.

• getmark() and setmark() always raise an exception, and getmarkers() always returns None (do nothing else): these methods are not very useful.
• Wave_write methods, getmark(), setmark() and getmarkers(), are not documented
• None of these methods are tested

Linked PRs

• gh-105096: Deprecate wave getmarkers() method #105098
• gh-105096: Reformat wave documentation #105136
• [3.12] gh-105096: Reformat wave documentation (#105136) #105138
• [3.11] gh-105096: Reformat wave documentation (#105136) (#105138) #105155