[NFC][TSan] Move RestoreStack before ScopedReport in ReportDestroyLocked (#228643)

Run RestoreStack in its own lock scope before constructing ScopedReport
in ReportDestroyLocked (matching ReportRace). This avoids acquiring
ScopedErrorReportLock or symbolizing the current stack if RestoreStack
fails, and avoids holding slot_lock and slot_mtx while populating the
ScopedReport.

Assisted-by: Gemini
GitOrigin-RevId: 13729747c5d03646f09a9f7bdecfe491254bead9