Install and run GitHub Copilot CLI directly from gh

Since we deprecated the GitHub Copilot in the CLI extension in favor of the new agentic GitHub Copilot CLI, we want to give developers using gh a simple way to get started using our most powerful terminal assistant.

• gh copilot will prompt to install, then run Copilot CLI
• gh copilot <args> will execute the Copilot CLI, forwarding any arguments and flags

For more information and usage options, run gh copilot --help.

What's Changed

✨ Features

• gh copilot: add native copilot command to execute/install copilot cli by @devm33 in #12444
• gh cache delete: allow for delete all caches for a ref by @davidspek in #12101
• gh pr create: error when head and base refs are identical in pr create by @majiayu000 in #12376

📚 Docs & Chores

• Fix Windows asset URL in copilot command tests by @babakks in #12500
• Update contributing guidelines for clarity by @BagToad in #12505

New Contributors

• @devm33 made their first contribution in #12444
• @davidspek made their first contribution in #12101

Full Changelog: v2.85.0...v2.86.0