libktx: Update to 4.4.0

thirdparty/libktx/lib/texture2.h

@@ -8,7 +8,7 @@
 
 /**
  * @internal
- * @file texture2.h
+ * @file
  * @~English
  *
  * @brief Declare internal ktxTexture2 functions for sharing between
@@ -46,9 +46,6 @@ typedef struct ktxTexture2_private {
                                         index offset. */
 } ktxTexture2_private;
 
-KTX_error_code
-ktxTexture2_LoadImageData(ktxTexture2* This,
-                          ktx_uint8_t* pBuffer, ktx_size_t bufSize);
 
 KTX_error_code
 ktxTexture2_constructCopy(ktxTexture2* This, ktxTexture2* orig);