Deprecation warning on Ruby 3.4

[MatheusRich]

Describe the bug
When running this gem with RUby 3.4 I get the following warning:

/.asdf/installs/ruby/3.4.1/lib/ruby/gems/3.4.0/gems/ruby-openai-7.3.1/lib/openai/compatibility.rb:1: warning: ::Ruby is reserved for Ruby 3.5

To Reproduce

1. Install the gem with RUby 3.4
2. Enable warnings with Warning[:deprecated] = true
3. Run any code

Expected behavior
No warnings.

Desktop (please complete the following information):

• OS: MacOS
• Version 15.2

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I believe we'll need to remove the compatibility module to support 3.5 eventually.

[alexrudall]

Thanks @MatheusRich, released in ruby-openai v8