Don't import graph under Windows

scripts/wk/hw/cpu.py

@@ -2,6 +2,7 @@
 # vim: sts=2 sw=2 ts=2
 
 import logging
+import platform
 import re
 import subprocess
 
@@ -9,14 +10,16 @@ from typing import TextIO
 
 from wk import exe
 from wk.cfg.hw import CPU_TEMPS
+from wk.os.mac import set_fans as macos_set_fans
+from wk.std import PLATFORM
+from wk.ui import ansi
+
+if platform.system() != 'Windows':
   from wk.graph import (
     export_cpu_graph,
     upload_to_imgur,
     upload_to_nextcloud,
     )
-from wk.os.mac import set_fans as macos_set_fans
-from wk.std import PLATFORM
-from wk.ui import ansi
 
 
 # STATIC VARIABLES