Solve some Sendable warnings from the Swift 6 compiler

Sources/MySQLKit/MySQLConnectionSource.swift

@@ -37,4 +37,4 @@ public struct MySQLConnectionSource: ConnectionPoolSource {
     }
 }
 
-extension MySQLConnection: ConnectionPoolItem {}
+extension MySQLNIO.MySQLConnection: AsyncKit.ConnectionPoolItem {}  // Fully qualifying the type names implies @retroactive

Sources/MySQLKit/MySQLDataDecoder.swift

@@ -8,15 +8,18 @@ import NIOFoundationCompat
 /// Types which conform to `MySQLDataConvertible` are converted directly to the requested type. For other types,
 /// an attempt is made to interpret the database value as JSON and decode the type from it.
 public struct MySQLDataDecoder: Sendable {
+    /// A wrapper to silence `Sendable` warnings for `JSONDecoder` when not on macOS.
+    struct FakeSendable<T>: @unchecked Sendable { let value: T }
+
     /// The `JSONDecoder` used for decoding values that can't be directly converted.
-    let json: JSONDecoder
+    let json: FakeSendable<JSONDecoder>
 
     /// Initialize a ``MySQLDataDecoder`` with a JSON decoder.
     ///
     /// - Parameter json: A `JSONDecoder` to use for decoding types that can't be directly converted. Defaults
     ///   to an unconfigured decoder.
     public init(json: JSONDecoder = .init()) {
-        self.json = json
+        self.json = .init(value: json)
     }
 
     /// Convert the given `MySQLData` into a value of type `T`, if possible.
@@ -43,7 +46,7 @@ public struct MySQLDataDecoder: Sendable {
                 return try T.init(from: NestedSingleValueUnwrappingDecoder(decoder: self, data: data))
             } catch is SQLCodingError where [.blob, .json, .longBlob, .mediumBlob, .string, .tinyBlob, .varString, .varchar].contains(data.type) {
                 // Couldn't unwrap it, but it's textual. Try decoding as JSON as a last ditch effort.
-                return try self.json.decode(T.self, from: data.buffer ?? .init())
+                return try self.json.value.decode(T.self, from: data.buffer ?? .init())
             }
         }
     }

Sources/MySQLKit/MySQLDataEncoder.swift

@@ -8,15 +8,18 @@ import NIOFoundationCompat
 /// Types which conform to `MySQLDataConvertible` are converted directly to `MySQLData`. Other types are
 /// encoded as JSON and sent to the database as text.
 public struct MySQLDataEncoder: Sendable {
+    /// A wrapper to silence `Sendable` warnings for `JSONEncoder` when not on macOS.
+    struct FakeSendable<T>: @unchecked Sendable { let value: T }
+
     /// The `JSONEncoder` used for encoding values that can't be directly converted.
-    let json: JSONEncoder
+    let json: FakeSendable<JSONEncoder>
 
     /// Initialize a ``MySQLDataEncoder`` with a JSON encoder.
     ///
     /// - Parameter json: A `JSONEncoder` to use for encoding types that can't be directly converted. Defaults
     ///   to an unconfigured encoder.
     public init(json: JSONEncoder = .init()) {
-        self.json = json
+        self.json = .init(value: json)
     }
 
     /// Convert the given `Encodable` value to a `MySQLData` value, if possible.
@@ -42,7 +45,7 @@ public struct MySQLDataEncoder: Sendable {
                 return MySQLData(
                     type: .string,
                     format: .text,
-                    buffer: try self.json.encodeAsByteBuffer(value, allocator: .init()),
+                    buffer: try self.json.value.encodeAsByteBuffer(value, allocator: .init()),
                     isUnsigned: true
                 )
             }
@@ -165,3 +168,6 @@ public struct MySQLDataEncoder: Sendable {
         }
     }
 }
+
+/// This conformance suppresses a slew of spurious warnings in some build environments.
+extension MySQLNIO.MySQLProtocol.DataType: @unchecked Swift.Sendable {} // Fully qualifying the type names implies @retroactive

Sources/MySQLKit/MySQLRow+SQL.swift

@@ -11,7 +11,7 @@ extension MySQLRow {
     }
 }
 
-extension MySQLNIO.MySQLRow: @unchecked Sendable {} // Fully qualifying the type name implies @retroactive
+extension MySQLNIO.MySQLRow: @unchecked Swift.Sendable {} // Fully qualifying the type names implies @retroactive
 
 /// An error used to signal that a column requested from a `MySQLRow` using the `SQLRow` interface is not present.
 struct MissingColumn: Error {

Sources/MySQLKit/Optional+MySQLDataConvertible.swift

@@ -1,7 +1,7 @@
 import MySQLNIO
 
 /// Conforms `Optional` to `MySQLDataConvertible` for efficiency.
-extension Optional: MySQLDataConvertible where Wrapped: MySQLDataConvertible {
+extension Swift.Optional: MySQLNIO.MySQLDataConvertible where Wrapped: MySQLNIO.MySQLDataConvertible {
     // See `MySQLDataConvertible.init?(mysqlData:)`.
     public init?(mysqlData: MySQLData) {
         if mysqlData.buffer != nil {