LeafletSettingsElementSettingsTrait::getDefaultSettings() includes a `weight` property that is not the config schema for the leaflet_formatter_default formatter

Problem/Motivation

In Drupal CMS, we are getting schema errors in our tests because, although none of our config sets the weight property on fields which use the leaflet_formatter_default field formatter, it gets added anyway because it's in LeafletSettingsElementSettingsTrait::getDefaultSettings(), but is not defined in config schema.

Proposed resolution

Either remove the property from getDefaultSettings() (if it shouldn't exist), or add it to config schema.