ref: Refactor SentryClient init

[github-actions]

Note

The pull request "ref: Refactor SentryClient init" was created by @noahsmartin but did not reference an issue. Therefore this issue was created for better visibility in external tools like Linear.

The many paths through this logic confused me, but it wasn't actually confusing, it was just written confusingly so I cleaned it up.

For example this allowed me to delete deleteOldEnvelopeItems which was only ever YES

#skip-changelog

[linear]

COCOA-884