Incorrect minimum Ruby version

[nsmmrs]

After upgrading from 0.2.1 to 0.2.2, I started getting this error when running (unrelated) rake tasks:

rake aborted!
SyntaxError: /app/bundle/ruby/2.7.0/gems/singed-0.2.2/lib/singed/kernel_ext.rb:2: syntax error, unexpected ')', expecting local variable or method
...interval: 1000, io: $stdout, &)
...                              ^
/app/bundle/ruby/2.7.0/gems/singed-0.2.2/lib/singed/kernel_ext.rb:4: syntax error, unexpected ')'
    result = fg.record(&)
                        ^
/app/bundle/ruby/2.7.0/gems/singed-0.2.2/lib/singed/kernel_ext.rb:17: syntax error, unexpected `end', expecting end-of-input

This is because the "bare ampersand" block-forwarding was added in Ruby 3.1, but I'm still on 2.7.

I see this was due to a Standardrb auto-fix; not sure if standardrb lets you specify a desired level of backwards-compatibility or not.

As I'm not sure what's involved in updating a Rubygems release, I've neglected to make any commits, but I hope this is helpful.