Adopted the standard withCString for C strings throughout the library.

Sources/PlaydateKit/Graphics/Classes/Bitmap.swift

@@ -26,7 +26,7 @@ extension Graphics {
         /// Loads a bitmap from a file in the game's pdx or Data directory.
         public convenience init(path: String) throws(PlaydateError) {
             var error: UnsafePointer<CChar>?
-            let pointer = path.withPlaydateCString { gfx.pointee.loadBitmap.unsafelyUnwrapped($0, &error) }
+            let pointer = path.withCString { gfx.pointee.loadBitmap.unsafelyUnwrapped($0, &error) }
             guard let pointer else { throw PlaydateError(cString: error) }
             self.init(pointer: pointer, isOwned: true)
         }
@@ -77,7 +77,7 @@ extension Graphics {
         /// Replaces the bitmap's contents with the image at `path`.
         public func load(path: String) throws(PlaydateError) {
             var error: UnsafePointer<CChar>?
-            path.withPlaydateCString { gfx.pointee.loadIntoBitmap.unsafelyUnwrapped($0, pointer, &error) }
+            path.withCString { gfx.pointee.loadIntoBitmap.unsafelyUnwrapped($0, pointer, &error) }
             cachedSize = nil
             if let error { throw PlaydateError(cString: error) }
         }