ci: check-qml fails after 2026-05-31 flake update (qmlformat outputs empty for files using `as` type cast)

[Mentigen]

What happened

After the [CI] chore: update flake commit from 2026-05-31 (63bb827), the check-qml CI job fails on any open PR. The formatter outputs an empty file for modules/bar/Bar.qml (and likely other files), causing diff to see the entire file as removed.

Observed via PR #1457, which does not touch Bar.qml at all.

Root cause

Bar.qml (and several other files in the repo) use the inline type assertion syntax introduced in Qt 6:

const loader = repeater.itemAt(i) as WrappedLoader;

Some versions of qmlformat do not parse the as TypeName expression correctly and silently output nothing instead of the formatted file. When the flake was updated today, the pinned Qt/qmlformat version appears to have changed to one that regresses on this syntax.

The CI script exits on the first failure:

for file in (string match -v 'build/*' **.qml)
    /usr/lib/qt6/bin/qmlformat $file | diff -u $file - || exit 1
end

modules/bar/Bar.qml comes first alphabetically, so the job stops there.

Possible fixes

• Pin the flake to a Qt version where qmlformat handles as correctly.
• Upgrade to a Qt version where the regression is fixed.
• Rewrite the affected as casts to a style that the current qmlformat accepts (if one exists).
• Skip files that use as casts in the format check until upstream qmlformat support is stable.

Affected files

At minimum modules/bar/Bar.qml. Other files using the same syntax are likely affected too but the CI exits before reaching them.