🎵 Whatever Lola wants, Lola gets

Address RxSwiftCommunity/RxGRDB#72

Based on https://github.com/swiftlang/swift-evolution/blob/main/proposals/0337-support-incremental-migration-to-concurrency-checking.md#preconcurrency-attribute-on-nominal-declarations

See also https://www.massicotte.org/preconcurrency#working-with-swift-5

"Whatever Lola wants, Lola gets" because the Swift language is a blind and cruel mistress.

GRDB/Core/DatabaseRegionObservation.swift

@@ -83,6 +83,7 @@ extension DatabaseRegionObservation {
     /// - parameter onChange: The closure to execute when a transaction has
     ///   modified the observed region.
     /// - returns: A DatabaseCancellable that can stop the observation.
+    @preconcurrency // For RxGRDB, see <https://github.com/RxSwiftCommunity/RxGRDB/issues/72#issuecomment-2631125658>
     public func start(
         in writer: any DatabaseWriter,
         onError: @escaping @Sendable (Error) -> Void,