Only load what is required from cgi for Ruby 3.5

[Earlopain]

In Ruby 3.5, most of the cgi gem is removed. Only methods relating to escaping/unescaping are retained.

On versions before Ruby 3.5, cgi/util must be required for correct functionality.

https://bugs.ruby-lang.org/issues/21258

---

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

1. To make sure we include your contribution in the release notes, please make sure to add description entry for your changes in the "unreleased changes" section of the CHANGELOG.md file (at corresponding gem). For the description entry, please make sure it lives in one line and starts with Feature or Issue in the correct format.

2. For generated code changes, please checkout below instructions first:
   https://github.com/aws/aws-sdk-ruby/blob/version-3/CONTRIBUTING.md

Thank you for your contribution!

[mullermp]

Do we need cgi as a dependency as well? Is it being removed as a bundled gem entirely, or are you saying that parts are being removed but cgi is still bundled?

[mullermp]

Are these actually equivalent? Is there any supporting documentation for these implementations?

[Earlopain]

CGI.parse: https://docs.ruby-lang.org/en/3.4/CGI.html#method-c-parse
URI.decode_www_form: https://docs.ruby-lang.org/en/3.4/URI.html#method-c-decode_www_form

It treats it as x-www-form-urlencoded, which uses the query string format of key=value&key2=value.

They return data in a slightly different format. CGI.parse returns a hash, URI.decode_www_form an array of 2-element arrays. For tests to just check against this is fine, if it were exposed to users it would need a different solution.

[mullermp]

@Earlopain I've performed a review. Do you know for sure this change is being made? It seems a bit premature since Ruby 3.5 is not released and the cgi work is not complete.

[Earlopain]

Thanks for taking a look.

Do we need cgi as a dependency as well? Is it being removed as a bundled gem entirely, or are you saying that parts are being removed but cgi is still bundled?

Things like CGI::Cookie are being removed. All the escape/unescape methods will continue to work without cgi as a dependency. So there is no need to declare it. It is being done a bit differently than the other bundled gems in the past (and rightly so, since every other gem uses these escape/unescape methods).

Do you know for sure this change is being made? It seems a bit premature since Ruby 3.5 is not released and the cgi work is not complete.

Ruby already did the work to handle this change in their own code (erb, bundler, rdoc, others I can't think about). Of course I can't say it definitly, but I am very sure. But we can wait until 3.5-preview2 (preview1 was released in april) or something along the lines, it's no rush from me.

[mullermp]

Thanks. I think it would be prudent to wait until Ruby 3.5 preview confirms the changes. I've prepared this release with changelogs.