P2 - Clear all segments that can be transcoded from the livepeer-production-failed-transcodes bucket

clear segments that cannot be transcoded from fail segment bucket Why? Makes it easier to do fail segment transcode debugging.

The `livepeer-production-failed-transcodes` bucket is used for running transcode tests using segments that previously failed. Many of these segments likely can be transcoded now as fixes have been shipped. We should remove those segments to cleanup the bucket.