[Ruby 3.0] Fix Ruby 2.7's deprecation warnings

[ainame]

Checklist

• I've run bundle exec rspec from the root directory to see all new and existing tests pass
• I've followed the fastlane code style and run bundle exec rubocop -a to ensure the code style is valid
• I've read the Contribution Guidelines
• I've updated the documentation if necessary.

Motivation and Context

As per plan #17931, I've been working on Ruby 3.0 migration in fastlane project. Prior to this PR, I have enabled CI testing for Ruby 2.7 #17861. We can now run unit testing in Ruby 2.7 in order to see if there are deprecation warnings by leveraging the new option "-W:deprecated" in Ruby 2.7.2.

Deprecation warnings are off by default on 2.7.2 and later. You can turn on deprecation warnings by specifying the -w or -W:deprecated option at the command-line.
https://www.ruby-lang.org/en/news/2020/10/02/ruby-2-7-2-released/

There is a minor breaking change in Ruby 3.0 which is called "Separation of positional and keyword arguments". In short, the below code won't run on Ruby 3.0. Previously you could pass a Hash object as keyword arguments to a method, but now you need to either use ** to turn Hash into keywords arguments or simply use keywords to pass parameters. This is the most common case we need to fix.

def say(string:)
  puts string
end
params = { string: "Hello" }

# Bad in Ruby 3.0
say(params)
say({ string: "Hello" })

# Good in Ruby 3.0
say(string: "Hello")
say(**params)
say(**{ string: "Hello" })

See details below.
https://www.ruby-lang.org/en/news/2019/12/12/separation-of-positional-and-keyword-arguments-in-ruby-3-0/

Thanks to the warnings, I could fix them as far as I got. There might be more within this project potentially but it's impossible to review every single line of code. So I expect the community to report something not working on Ruby 3.0 if they find once the whole migration is done in future🙇

Note that this PR mostly covers the codebase within this project. There are also the same warnings from dependencies. I will work on it in another PR.

Description

Other than adding ** or giving parameters to keyword arguments, I did the followings.

• Update Rakefile and .circleci/config.yml to prevent regressions by monitoring deprecation warnings
• Clean up unused attributes in FastlaneCore::Project
• Using keywords arguments in ERB.new
• Relax dependencies' versioning in gemspec for testing libraries, which allows us to fix some warnings quickly

This is the list I used as a reference of where to fix. As I mentioned, I didn't try to fix issues in slack-notifier and rspec-mocks in this list.
https://gist.github.com/ainame/d7f1c4d2fb07f139d3a0f064d4cbda75

Testing Steps

CI passed unit tests on all the environments. I will give it a try on my project briefly, too🙂

[ainame]

Merged the main branch into this and no new warning is there.

[joshdholtz]

This looks good to me! LGTM 🥳

[ainame]

This branch has the latest change in the main branch and no new warning. It's good to merge now.

[fastlane-bot]

Congratulations! 🎉 This was released as part of fastlane 2.178.0 🚀