v69.0.0

Full changelog

• General
  • BREAKING CHANGE: Replaced the client-side storage backend with a SQLite-powered one.
    This is major change and large refactoring of the Glean SDK internals, but has very limited breaking changes in the
    public API (breaking changes in the Rust API only).
    Data is migrated from the old rkv-powered storage to the SQLite database on first start with this Glean SDK version.
    The Rkv data is retained for now. Only the SQLite-backed data is written to for new metric recordings.
    New glean.migration.* metrics were added to monitor and validate the migration process.
    Other monitoring metrics are preserved.
    The glean.database.rkv_load_error has been replaced by a more generic glean.database.load_error with similar semantics.