refactor: Update Starscream to 4.0.8

[dplewis]

New Pull Request Checklist

• [x] I am not disclosing a vulnerability.
• [x] I am creating this PR in reference to an issue.

Issue Description

We need to update the version of Starscream to support Privacy Manifest requirements.

https://github.com/daltoniam/Starscream/compare/4.0.6...4.0.8

ref: https://github.com/parse-community/Parse-SDK-iOS-OSX/issues/1785

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[parseplatformorg]

🎉 This change has been released in version 4.1.0