ci(mergify): upgrade configuration to current format

[mergify]

Caution

Your Mergify configuration uses deprecated fields that Mergify cannot migrate automatically.
This pull request does not modify your configuration — it exists to make sure you see this notice.

Hey there! 👋

We've noticed that your Mergify configuration is using some deprecated fields. Mergify usually updates them for you automatically, but these ones have no exact automatic replacement — migrating them could change how your rules behave, so they need your judgment:

• queue_rules → commit_message_template: The commit_message_template setting is deprecated. Use the declarative commit_message_format instead: https://docs.mergify.com/workflow/actions/merge#migrating-from-commit_message_template (deadline: 2026-09-30)

Here is what stopped Mergify on each one:

• queue_rules → commit_message_template in rule default: This template has no exact commit_message_format equivalent. Rewrite it by hand.

Do not procrastinate! You must upgrade your configuration before 2026-09-30, otherwise your configuration will stop working.

What should I do?

Update the fields listed above directly in your configuration file, following the documentation linked in each item. Once your default branch no longer uses them, this pull request will close automatically — there is nothing to merge here.

Got Questions? We've Got Answers! 🙌

Why didn't Mergify migrate this for me?

The new syntax cannot reproduce your current configuration exactly. Rather than risk changing your workflows' behavior, we leave the migration to you.

What if I run into issues or have concerns?

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

Happy merging! 🎉

[jnhsigmap]

I tried to close this because it's wrong (#1107) and opened an issue to fix properly #1108 🙂

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.69%. Comparing base (364f91f) to head (7d5ecea).

Additional details and impacted files

@@           Coverage Diff           @@
##           stable    #1109   +/-   ##
=======================================
  Coverage   62.69%   62.69%           
=======================================
  Files         161      161           
  Lines       26989    26989           
=======================================
  Hits        16922    16922           
  Misses      10067    10067           

Flag	Coverage Δ
rust	62.69% <0.00%> (ø)

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