Don't send 'accept-encoding' header in HttpIO

What does this MR do?

Net::HTTP does not automatically decompress requests sent with a range header. HttpIO#request sets the range header, but also includes the default accept-encoding: gzip;q=1.0,deflate;q=0.6,identity;q=0.3 header as well. If the accept-encoding header is honored and the response is gzipped then its body will be unreadable.

This change removes the accept-encoding header from requests sent by HttpIO, ensuring responses are not gzipped.

Closes #212609 (closed)

Does this MR meet the acceptance criteria?

Conformity

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