Adds Ruby 3.0 to CI Matrix

[iMacTia]

Description

Adds Ruby 3.0 to CI Matrix

Additional Notes

• Should we keep Ruby head as experimental for future Ruby releases?

[olleolleolle]

Timeouts are reported in a wonky way: on 3.0

https://github.com/lostisland/faraday/pull/1226/checks?check_run_id=1622851358#step:6:4461

[iMacTia]

@olleolleolle problem with Net::HTTP::Persistent timeouts it fixed 🙌
What do you think about keeping the ruby-head in the matrix? Is it still useful now that we added 3.0?

[olleolleolle]

Oh, I think we can throw it out for the time being. Useful trick to have when big changes coming ahead. But not for all days.

Great news!

[iMacTia]

Thanks, makes sense.
Also, I just realised you already identified and attempted to fix this issue in #1154 !
In this branch, I raise a Faraday::Timeout exception to keep it consistent with the older behaviour, but does that mean we can now support Net::HTTP::Persistent also for older rubies 🤔?

So at the moment, we can see all tests are passing, but v4.0 is used only for Ruby 3.0 (see Gemfile)
I'll update the Gemfile to allow v4.0 also for lower rubies and give it a try 👍