Deprecate tuning enum and trainer properties (#15100)

Author: rohitgr7

src/pytorch_lightning/CHANGELOG.md

@@ -91,6 +91,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Deprecated `TrainerFn.TUNING`, `RunningStage.TUNING` and `trainer.tuning` property ([#15100](https://github.com/Lightning-AI/lightning/pull/15100)
 
 
+- Deprecated `TrainerFn.TUNING`, `RunningStage.TUNING` and `trainer.tuning` property ([#15100](https://github.com/Lightning-AI/lightning/pull/15100)
+
+
 ### Removed
 
 - Removed the deprecated `Trainer.training_type_plugin` property in favor of `Trainer.strategy` ([#14011](https://github.com/Lightning-AI/lightning/pull/14011))