The reason this was happening was an unfortunate oversight in the
migration logic. The code that was attempting to parse the skin settings
as `int` was firing regardless of whether a skin migration from EF to
realm had already occurred. If it had occurred, the skin setting would
contain a GUID rather than an integer, and therefore fail to parse, and
therefore implicitly fallback to a EF skin ID of 0 which would be the
default skin.
Fix by not running the setting migrating logic at all when there are no
EF skins to migrate.
* `RealmRulesetSetting` was added in 2021.916.0.
* `RealmKeyBinding` was added in 2021.703.0.
Attempting to upgrade from older releases than the above would cause
migrations up to schema versions 10 and 11 to fail.