Ruby 3.3

[Earlopain]

Test against Ruby 3.3 and supress new warnings.

Ruby 3.3 will warn if base64 or bigdecimal is required without requiring it in the gemspec. The base64 gem is trivial to replace, but bigdecimal I added to the gemspec.

base64:

• https://github.com/rack/rack/pull/2110
• https://github.com/rubocop/rubocop/pull/12313
• https://github.com/newrelic/newrelic-ruby-agent/pull/2378
• https://github.com/lostisland/faraday/pull/1541

bigdecimal:

• https://github.com/rails/rails/pull/49039

[Earlopain]

@sferik could you check this out if you got some time?

[Earlopain]

Thank you!