Update test_build_gui_context.py

from suggestions

Author: logan-keede

tests/commands/convert/test_build_gui_context.py

@@ -2,4 +2,4 @@ def test_overrides_are_used(convert_command):
     overrides = {"gui_framework": "Toga", "console_app": "Console"}
     out = convert_command.build_gui_context({}, overrides)
     assert out == {"gui_framework": "None", "console_app": "true"}
-    assert overrides["gui_framework"] == "Toga"
+    assert overrides == {"gui_framework": "Toga", "console_app": "Console"}