Release `26.3.0`

[kenodegard]

Summary

Placeholder for conda-build 26.3.0 release.

Pilot
Co-pilot

Tasks

The week before release week

• Create release branch (named 26.3.x)
• Ensure release candidates are being successfully built (see conda-canary/label/rc-conda-build-26.3.x)
• Complete outstanding PRs
• Check for deprecated features
• Test release candidates

Release week

• Create release PR (see release process)
• Create Zulip thread on #releases
  • Announce 26.3.0 in-progress
• Publish release
• Merge 26.3.x back into main
• Activate the 26.3.x branch on ReadTheDocs
• Bump/update feedstocks
  • Anaconda, Inc.'s feedstock
  • conda-forge feedstock
• Hand off to packaging team(s)
• Announce release
  • Create & publish conda.org blog post
  • Post on Zulip thread