[Refactor] Fix incorrect Promise.all usage in app.ts

[gonzaloriestra]

WHY are these changes introduced?

The preDeployValidation function in packages/app/src/cli/models/app/app.ts was not correctly awaiting the validation of all extensions. It was using Promise.all([this.allExtensions.map(...)]), which creates an array containing a single element (the array of promises returned by .map()). Promise.all then resolves immediately because it sees an array of non-promise values (the array itself).

WHAT is this pull request doing?

Fixed the incorrect Promise.all usage by removing the unnecessary outer array brackets. Now it correctly awaits all validation promises: Promise.all(this.allExtensions.map(...)).

How to test your changes?

Run the tests for the app model:
pnpm --filter @shopify/app vitest run app.test.ts

Duplicate check

I ran git log --grep="Jules" --grep="Refactor" --pretty=format:"%h %s" --max-count=50 to check for previous similar PRs.

• 088a35a45 [Refactor] Consolidate command execution in system.ts: Consolidates logic in a different subsystem.
• aa120fbcf [Refactor] Optimize copyDirectoryContents with glob cwd: Focuses on path handling and performance in cli-kit.
• b79412428 [Refactor] Remove redundant Knip ignoreDependencies entries: Addresses knip configuration hints.

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've considered analytics changes to measure impact
• The change is user-facing — I've identified the correct [bump type] (patch for bug fixes · minor for new features · major for [breaking changes]) and added a changeset with pnpm changeset add

PR Label: Jules

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PR created automatically by Jules for task 14262157258669614203 started by @gonzaloriestra

[google-labs-jules]

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