Ignore mosaicml logger for exception if excephook is active

[jjanezhang]

Ignore mosaicml logger for exception if excephook is active

Before we remove the logger all together (re: #1292) we want to first test catching exceptions with a flag. This prevents us from logging an exception twice. I will run tests that turn the logger off in favor of overriding the excepthook to make sure the intended before still holds for finetuning.

Ran a test on dbx-staging to confirm that the flag works. We will have to update the foundry image used for finetuning to incorporate this change.

[dakinggg]

there are more places to do this, can you grep foundry for .log_exception and replace all of them (unless there was a reason you only did some)?