[logging] less startup noise (#7526)
This PR removes some and enables removing other startup noise -
especially when it's replicated rank-times and doesn't carry any
informative payload.
1. add `--log_level` flag which sets the launcher's logger to a desired
setting - defaulting to `logging.INFO` for now for BC, but will change
to `logging.WARNING` in v1
2. add `--quiet/-q` flag which sets the launcher's logger to
`logging.ERROR` which essentially disables startup info messages
3. change the logging defaults elsewhere to `logging.WARNING` (main
impact is the accelerator.py), once deepspeed started the frameworks
control its loglevel for each rank, so the tricky part is this pre-start
stage info logs. this part is breaking BC as there is no machinery to
set the logger level for `real_accelerator.py`)
4. builder is changed to non-verbose (BC breaking)
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Signed-off-by: Stas Bekman <stas@stason.org>
Co-authored-by: Olatunji Ruwase <tunji.ruwase@snowflake.com>
