assign_temp_parachain_slot: TxDescriptor<{
    id: number;
    lease_period_start: PolkadotRuntimeCommonAssignedSlotsSlotLeasePeriodStart;
}>

Assign a temporary parachain slot. The function tries to create a lease for it immediately if SlotLeasePeriodStart::Current is specified, and if the number of currently active temporary slots is below MaxTemporarySlotPerLeasePeriod.