Update listings channel commission

This endpoint is deprecated — do not use it. Migrate to PUT /channel-commissions-v2/unit-type/{unitTypeId} and PUT /channel-commissions-v2/unit-type/{unitTypeId}/level-configurations. No removal date has been announced.

Migration notes: send one listing at a time via PUT /channel-commissions-v2/unit-type/{unitTypeId} (body is an array of channel/source commission definitions, not the v1 keyed-by-channel object). Map v1 useAccountSettings to PUT /channel-commissions-v2/unit-type/{unitTypeId}/level-configurations (true → levelEntityType: ACCOUNT, false → UNIT_TYPE).

This endpoint allows you to send Guesty an updated amount for channel commissions.
Providing an amount to an existing integration object or manual source will update its channel commission value. If the integration object or manual source do not exist, they will be added.

example for bookingCom: {channelCommissions: [{listingId: "923892d53f4f56cfcb25586d", bookingCom: {tax: 10, commission: {value: 5, of: ["ACCOMMODATION_FARE"]}}}]}