Update subosito/flutter-action action to v2.12.0

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
subosito/flutter-action	action	minor	v2.11.0 -> v2.12.0

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Release Notes

subosito/flutter-action (subosito/flutter-action)

### [`v2.12.0`](https://togithub.com/subosito/flutter-action/compare/v2.11.0...v2.12.0) [Compare Source](https://togithub.com/subosito/flutter-action/compare/v2.11.0...v2.12.0)

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Configuration

📅 Schedule: Branch creation - "before 5pm on friday" in timezone Europe/Berlin, Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

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• [ ] If you want to rebase/retry this PR, check this box

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