Bridge cask flight step migrations (19/26)

[MikeMcQuaid]

Repeat of #23194

Tap migrations cannot replace every cask flight block atomically. Matching step and Ruby forms must coexist until the tap reaches zero hooks.

• retain both artifacts instead of discarding either declaration
• execute declarative steps before the matching Ruby flight block
• use the shared command output default in every step phase

AI disclosure: using OpenAI Codex 5.6 Sol max with local review and testing.

[Copilot]

Pull request overview

This PR updates the Cask DSL and artifact ordering to support an incremental migration from Ruby flight blocks (preflight, postflight, etc.) to declarative *_steps stanzas by allowing both forms to coexist and ensuring the steps execute before the corresponding Ruby block.

Changes:

• Remove the DSL conflict logic that previously warned and discarded flight blocks when matching *_steps stanzas were present.
• Adjust artifact sort order so PreflightSteps run before PreflightBlock (matching the existing PostflightSteps/PostflightBlock ordering).
• Update/install test coverage to use the non-deprecated step DSL method names and assert “steps then flight block” execution during the bridge period.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
Library/Homebrew/test/cask/artifact/install_steps_spec.rb	Updates step DSL usage to canonical names and adds a migration test asserting that preflight_steps run before preflight.
Library/Homebrew/cask/dsl.rb	Removes the “steps override flight block with warning” behavior so both artifacts are retained during migration.
Library/Homebrew/cask/artifact/abstract_artifact.rb	Reorders artifact sort precedence so PreflightSteps execute before PreflightBlock.

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[p-linnane]

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