Always show the 'Available' option in the keyframe menu, so that the shown menu items are stable. This helps to keep hotkey assignments for the menu items remain the same. Note that this isn't a full guarantee yet, as the 'Active Keying Set' option is also still conditionally added, depending on whether a keying set was chosen or not. This will be addressed in another commit. Pull Request: https://projects.blender.org/blender/blender/pulls/136952