message: Handle tkinter not importing and disable relevant test. Closes
diff: @@ -2,10 +2,20 @@ import renderdoc as rd
  import rdtest
  import os
  +try:
  + import tkinter
  +except ImportError as ex:
  + tkinter = None
  class D3D12_RGP_Capture(rdtest.TestCase):
  demos_test_name = 'D3D12_Simple_Triangle'
  + def check_support(self):
  + if tkinter is None:
  + return False, 'tkinter is required but not available'
  +
  + return super().check_support()
  +
  # Need to enable RGP mode before opening the capture
  def run(self):
  rd.SetConfigSetting("ExternalTool_RGPIntegration", "1")
  @@ -18,7 +28,6 @@ class D3D12_RGP_Capture(rdtest.TestCase):
  rdtest.log.print("RGP capture not tested")
  return
  - import tkinter
  # On D3D12 we need to create a real window
  window = tkinter.Tk()
  