Use io-console for Windows console support

[nobu]

Summary

• replace Reline's direct Windows Fiddle bindings with io-console APIs
• use IO#console_input_events for interruptible input event processing
• use io-console for TTY detection, console modes, cursor operations, screen updates, and key state checks
• remove the Windows-only fiddle development dependency
• add coverage for translating io-console key event hashes into Reline::KeyEventRecord

Motivation

Reline currently carries its own Win32 API bindings and input record parsing. Moving those responsibilities to io-console removes duplicated platform code, gives CRuby and JRuby the same Windows console path, and lets console input waits remain responsive to Ruby interrupts.

This PR depends on ruby/io-console#140. The Gemfile temporarily points at its development branch so this PR can test the integration before the required io-console version is released.

Validation

• Add Windows console support io-console#140 passes its complete GitHub Actions matrix on Windows, macOS, Linux, JRuby, and TruffleRuby
• the focused local Reline test could not start because the local Bundler cache had not checked out the Git-based io-console dependency; this PR's CI will install that dependency and exercise the integration