Simplify some internals, since S3 became strongly consistent

[pmleveque]

Is your idea related to a problem? Please describe.
As far as I remember, there were some protections against s3 eventual consistency. They are no longer needed.

https://aws.amazon.com/blogs/aws/amazon-s3-update-strong-read-after-write-consistency

Describe the solution you'd like
Simply some internals.

for instance:
https://github.com/awslabs/aws-data-wrangler/blob/dfad32e19b45439b54c26491325bfe183455954c/awswrangler/emr.py#L535

[igorborgest]

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