[FIX] 震度データベースのJSON typesを変更

[YumNumm]

概要

• city要素は下記schemaなので、修正

export const EqmonitorEarthquakeIntensityObservationCitySchema = v.object({
  name: v.string(),
  code: v.nullable(StringNumber),
  max_intensity: intensity,
  observation_points: v.array(EqmonitorEarthquakeIntensityObservationSchema),
});