Ruby 3.0 transition

First round of FTBFSes according to @kanashiro:

• ruby-bindex
• ruby-byebug
• ruby-curb
• ruby-escape-utils
• ruby-gd
• ruby-json
• ruby-libvirt
• ruby-ruby-magic-static
• ruby-serialport
• ruby-shadow
• ruby-sigar
• ruby-stackprof (has another RC bug other bug downgraded)

Problem is not Ruby 3:

• ruby-psych

Fixed (categorized as a RoM candidate):

• ruby-dataobjects-mysql
• ruby-kyotocabinet
• ruby-mmap2

RoM candidates:

• obexftp
• ruby-ferret