Standard weekly patch release

[1.4.3] - 2021-08-17

• Fixed plateau scheduler stepping on incomplete epoch (#8861)
• Fixed infinite loop with CycleIterator and multiple loaders (#8889)
• Fixed StochasticWeightAveraging with a list of learning rates not applying them to each param group (#8747)
• Restore original loaders if replaced by entrypoint (#8885)
• Fixed lost reference to _Metadata object in ResultMetricCollection (#8932)
• Ensure the existence of DDPPlugin._sync_dir in reconciliate_processes (#8939)

Contributors

@awaelchli @carmocca @justusschock @tchaton @yifuwang
If we forgot someone due to not matching commit email with GitHub account, let us know :]