Win32 libjxl uses pthreads, not native threads...

So, we can't use threads with these libs. :(
This is going to be a pain to build these due to the dependencies.

src/syncterm/GNUmakefile

@@ -39,11 +39,11 @@ ifdef win
  CFLAGS += -I${3RDP_ROOT}/win32.release/libjxl/include -DJXL_THREADS_STATIC_DEFINE -DJXL_STATIC_DEFINE
  LDFLAGS += -L${3RDP_ROOT}/${os}.release/libjxl/lib
  EXTRA_LIBS += -ljxl
- EXTRA_LIBS += -ljxl_threads
+ #EXTRA_LIBS += -ljxl_threads
  EXTRA_LIBS += -lbrotlidec
  EXTRA_LIBS += -lbrotlicommon
  EXTRA_LIBS += -lhwy
- CFLAGS += -DWITH_JPEG_XL -DWITH_JPEG_XL_THREADS -DWITH_STATIC_JXL
+ CFLAGS += -DWITH_JPEG_XL -DWITH_STATIC_JXL
  OBJS += $(MTOBJODIR)$(DIRSEP)libjxl$(OFILE)
 else
  ifeq ($(shell pkg-config libjxl --exists && echo YES), YES)