Release jruby-rack 1.2.7

[chadlwilson]

It'd be good to cut a 1.2.7 release from 1.2-stable as I've been able to successfully backport support for JRuby 10.0 and 10.1, along with Rails 8.0 to the stable 1.2.x version:

Raising this tracking issue so @kares or @headius can help me release.

• CHANGELOG is updated already
• diffs since release
  • Main changes (diffs aren't that scary; it's mainly just Rails spec scaffolding)
    • 10.0 compat: 1.2.x: Backport JRuby 10.0 and Rails 8.0 compatbility #419
    • 10.1 compat: 1.2.x: [fix] ensure compatibility with JRuby 10.1 #423

Tasks

• Review changelog (@chadlwilson)
• Ensure CI and functional tests are passing: https://github.com/jruby/jruby-rack/actions/runs/25800233165 (@chadlwilson)
• Sanity check example apps via Warbler with Jetty, Rails, Tomcat, Sinatra (@chadlwilson)
• both Maven and RubyGems release