ci(mergify): upgrade configuration to current format

[mergify]

Caution

The transformed Mergify configuration is invalid or still contains deprecated fields that Mergify could not migrate automatically.
This can happen when the deprecated fields live under a shared key or behind YAML anchors — Mergify cannot know what these define, so it cannot modify them — or when a value has no automatic equivalent and needs a manual rewrite.
In order for the configuration to be valid, you will need to manually modify it.
Here is what makes the configuration invalid:

• Extra inputs are not permitted @ root → pull_request_rules → item 0 → actions → queue → method → squash
• Extra inputs are not permitted @ root → pull_request_rules → item 0 → actions → queue → commit_message_template → {{ title }} (#{{ number }}) {{ body }}

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Hey there! 👋

We've noticed that your Mergify configuration is using some deprecated fields.

No worries—we've got your back! This automated PR updates your config to align with the newest standards, ensuring everything keeps running smoothly.

Do not procrastinate! You must upgrade your configuration before 2026-07-31, otherwise your configuration will stop working.

What's Changed?

• pull_request_rules → actions → delete_head_branch: The delete_head_branch action is deprecated. Use GitHub's native 'Automatically delete head branches' setting instead: https://docs.github.com/en/repositories/configuring-branches-and-merges-in-your-repository/configuring-pull-request-merges/managing-the-automatic-deletion-of-branches (deadline: 2026-07-31)
• queue_rules → conditions: conditions in queue rule configuration is deprecated. Use merge_conditions instead. (deadline: 2026-07-31)

Why This Matters

Keeping your configuration up-to-date means you'll benefit from the latest features and improvements Mergify has to offer. Plus, it helps prevent any unexpected hiccups down the road.

Got Questions? We've Got Answers! 🙌

Is this update safe to merge?

Almost! We got most of the way there, but a couple of manual steps are still needed before it's safe to merge — check what's flagged at the top of this description for what's left to do.

Do I need to do anything special after merging?

Yes — take care of the manual steps flagged at the top of this description first, then you're all set. It's also a good idea to give any custom configurations a quick look to ensure everything's in order.

What if I run into issues or have concerns?

We're here to help! Feel free to reach out to our support team anytime.

Thanks for being awesome and keeping your configuration up-to-date! If you have any thoughts or need a hand, don't hesitate to let us know.

Happy merging! 🎉