chore(ci): fix update screenshot action to account for existing screenshot

[liamdebeasi]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

The update screenshots test had an issue where updating existing screenshots (as opposed to adding new screenshots) was not working as intended.

Given two test runner:

Runner A that updates Screenshot 1
Runner B that updates Screenshot 2

When the results from Runner A were added to the project, we got an updated Screenshot 1 and the old Screenshot 2.

When the results from Runner B were added to the project, we got an updated Screenshot 2 and an old Screenshot 1. The result is that the updated Screenshot 1 was overwritten by the old Screenshot 1 that got added from Runner B.

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This new approach ensures that only the changed screenshots per-runner are added to the archive. The directory structure is preserved, so unzipping and moving the screenshots should allow screenshots to be merged without any conflicts.

Does this introduce a breaking change?

• Yes
• No

Other information