Adopted Span and MutableSpan for buffers across the library to adapt to Swift 6.4.

Sources/PlaydateKit/Graphics/Structures/Bitmap.Data.swift

@@ -1,18 +1,14 @@
 extension Graphics.Bitmap {
-    /// The bitmap's dimensions, row stride, and raw pixel/mask storage.
-    /// The pointers are owned by the bitmap.
-    public struct Data {
+    /// The bitmap's dimensions and row stride. Access the pixels themselves
+    /// with `withPixelData(_:)` and `withMaskData(_:)`.
+    public struct Data: Sendable {
         /// The bitmap's width, in pixels.
         public let width: Int
         /// The bitmap's height, in pixels.
         public let height: Int
-        /// The stride of one row of pixel data, in bytes.
+        /// The stride of one row of pixel (and mask) data, in bytes.
         public let rowBytes: Int
-        /// The bitmap's mask data, or `nil` if it has no mask. One bit per
-        /// pixel; rows are `rowBytes` wide.
-        public let mask: UnsafeMutablePointer<UInt8>?
-        /// The bitmap's pixel data. One bit per pixel; rows are `rowBytes`
-        /// wide.
-        public let data: UnsafeMutablePointer<UInt8>?
+        /// Whether the bitmap has a mask.
+        public let hasMask: Bool
     }
 }