Fix T82292: Set encoding for keymap export to UTF-8

Keymaps have previously been exported with an encoding dependent
on the current system locale. This caused issues when the
keymap contained non-ASCII characters, for instance in a string
property for an operator.

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D9449

release/scripts/modules/bl_keymap_utils/io.py

@@ -159,7 +159,7 @@ def keyconfig_export_as_data(wm, kc, filepath, *, all_keymaps=False):
     # not essential, just convenient to order them predictably.
     export_keymaps.sort(key=lambda k: k[0].name)
 
-    with open(filepath, "w") as fh:
+    with open(filepath, "w", encoding="utf-8") as fh:
         fw = fh.write
         fw("keyconfig_data = \\\n[")