[Tests] Remove filesystem mocks in result.test.ts

[gonzaloriestra]

Refactor packages/store/src/cli/services/store/execute/result.test.ts to use real filesystem operations with inTemporaryDirectory instead of vi.mock('@shopify/cli-kit/node/fs'). This improves test reliability and follows the project's testing standards.

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PR created automatically by Jules for task 15656458883640163586 started by @gonzaloriestra

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