Deprecate `LightningLoggerBase.close`

[ananthsub]

Proposed refactoring or deprecation

Motivation

This is a follow up to #9004 (reply in thread)
and
#9037

The base logger API has close defined
https://github.com/PyTorchLightning/pytorch-lightning/blob/089ae9b3e82ddc31942e315294e31e48c0a899db/pytorch_lightning/loggers/base.py#L312-L314

This is only implemented on https://github.com/PyTorchLightning/pytorch-lightning/blob/089ae9b3e82ddc31942e315294e31e48c0a899db/pytorch_lightning/loggers/test_tube.py#L197-L204

Given the test tube logger has since been deprecated, we can also deprecate this method off the base API as it's very unclear what the difference is between save/close/finalize currently.

This function is never called by the Trainer either, so deprecating it from the base logger API has minimal changes for users.

Pitch

• Deprecate close off the base API in v1.5
• Remove it from the API in v1.7

Additional context

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