indexeddb: Initialize DB version to zero. (#38819)

None of our automated tests were executing the initial DB setup code
because the requested version always matched.

Testing: Existing WPT coverage.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

components/net/indexeddb/idb_thread.rs

@@ -308,7 +308,6 @@ impl IndexedDBManager {
                             SqliteEngine::new(
                                 idb_base_dir,
                                 &idb_description,
-                                version,
                                 self.thread_pool.clone(),
                             )
                             .expect("Failed to create sqlite engine"),