`super().__init__()` usage for `_Joinable`

[awgu]

#61555 introduces the _Joinable abstract base class. Classes to be compatible with the generic join context manager _Join should inherit from _Joinable. However, because torch.nn.Module does not call super(Module, self).__init__(), DistributedDataParallel.__init__() must explicitly call the _Joinable constructor via _Joinable.__init__(). Similarly, because torch.optim.Optimizer does not call super(Optimizer, self).__init__(), ZeroRedundancyOptimizer.__init__() must explicitly call the _Joinable constructor.

If the Module and Optimizer constructors are modified to include the super().__init__() calls, then DistributeDataParallel and ZeroRedundancyOptimizer can remove the explicit call to the _Joinable constructor and instead rely on the method resolution order.

cc @pietern @mrshenli @pritamdamania87 @zhaojuanmao @satgera @rohan-varma @gqchen @aazzolini @osalpekar @jiayisuse @agolynski @SciPioneer @H-Huang @mrzzd @cbalioglu @gcramer23