Don't wrap request bodies if they are already Readables

[jakeonfire]

We don't need to wrap request bodies if they already conform to the ::Protocol::HTTP::Body::Readable interface. This way developers can use other kinds of Readables directly when making calls with Faraday.

Use-case: We need to make several requests to an API with chunks of a file in specific byte ranges. Protocol::HTTP::Body::File (from https://github.com/socketry/protocol-http) seems like a good candidate for this:

file_io = URI(file_url).open
byte_ranges.each do |first_byte, last_byte|
  file_io.open if file_io.closed? # it's closed at the end of each post
  body = Protocol::HTTP::Body::File.new(file_io, first_byte..last_byte)
  Faraday.post("https://example.com/uploads", body)
end

Types of Changes

• New feature.

Contribution

• I added tests for my changes.
• I tested my changes locally.
• I agree to the Developer's Certificate of Origin 1.1.

[jakeonfire]

i can write a spec if you think it'd be useful

[ioquatix]

This looks like a reasonable change, but yes, great to include a test to prevent regressions.

[jakeonfire]

test added 👍 are the truffleruby and jruby failures expected? they don't look related...