Support for Ruby 3

[davidjytang]

Hi! @Piotrovskyi, I appreciate your efforts on creating and maintaining this image. It has been helpful for me.

Recently I have run into this issue running on this image:

$ gem install fastlane -v 2.217.0
ERROR:  Error installing fastlane:
	The last version of google-cloud-env (~> 2.1) to support your Ruby & RubyGems was 2.1.1. Try installing it with `gem install google-cloud-env -v 2.1.1` and then running the current command again
	google-cloud-env requires Ruby version >= 3.0. The current ruby version is 2.7.1.83.

So naturally I tried the above suggestion like below:

$ gem install google-cloud-env -v 2.1.1
ERROR:  Error installing google-cloud-env:
	The last version of faraday-net_http (>= 2.0, < 3.4) to support your Ruby & RubyGems was 3.0.2. Try installing it with `gem install faraday-net_http -v 3.0.2` and then running the current command again
	faraday-net_http requires Ruby version >= 3.0.0. The current ruby version is 2.7.1.83.

And again

$ gem install faraday-net_http -v 3.0.2
Successfully installed faraday-net_http-3.0.2
$ gem install google-cloud-env -v 2.1.1
ERROR:  Error installing google-cloud-env:
	The last version of faraday (>= 1.0, < 3.a) to support your Ruby & RubyGems was 2.8.1. Try installing it with `gem install faraday -v 2.8.1` and then running the current command again
	faraday requires Ruby version >= 3.0. The current ruby version is 2.7.1.83.

As fastlane progresses, its requirement for ruby seems to progress as well. I wish to open this conversation with you on updating ruby to 3+.

I have taken a look at your dockerfile. The URL scheme for ruby is a little different, now at https://cache.ruby-lang.org/pub/ruby/3.3/ruby-3.3.4.tar.xz. To my untrained eyes, it seems we just replace the URL. However, I'm completely new in ruby world, I'm not sure if ruby 3 is an in-place replacement for ruby 2.7. I'm wondering you might be so kind as to upgrade the ruby dependency to increase the lifespan of this image.