pins.error: pin fan_toolhead_cooling_pin is an alias for gpio18

[board_pins btt_skr_pico_v1]
aliases:
# steppers
  x_step_pin=gpio11,  x_dir_pin=gpio10,   x_enable_pin=gpio12,  x_uart_pin=gpio9,   x_diag_pin=gpio4,   x_endstop_pin=gpio4,  x_tx_pin=gpio8,
  y_step_pin=gpio6,   y_dir_pin=gpio5,    y_enable_pin=gpio7,   y_uart_pin=gpio9,   y_diag_pin=gpio3,   y_endstop_pin=gpio3,  y_tx_pin=gpio8,
  z0_step_pin=gpio19, z0_dir_pin=gpio28,  z0_enable_pin=gpio2,  z0_uart_pin=gpio9,  z0_diag_pin=gpio25, z_endstop_pin=gpio25, z_tx_pin=gpio8,
  z1_step_pin=null,   z1_dir_pin=null,    z1_enable_pin=null,   z1_uart_pin=null,   z1_diag_pin=null,
  z2_step_pin=null,   z2_dir_pin=null,    z2_enable_pin=null,   z2_uart_pin=null,   z2_diag_pin=null,
  e_step_pin=gpio14,  e_dir_pin=gpio13,   e_enable_pin=gpio15,  e_uart_pin=gpio9,   e_diag_pin=gpio16,  e_endstop_pin=gpio16, e_tx_pin=gpio8,
# Extrusion
  e_heater_pin=gpio23,  e_sensor_pin=gpio27,
# accel
  adxl345_cs_pin=PD0, adxl345_sclk_pin=PD2, adxl345_mosi_pin=PD3,  adxl345_miso_pin=PD4, # SPI1 header is shared with SD card. This uses I/O header
# auto leveling
  bltouch_sensor_pin=gpio22,  bltouch_control_pin=gpio29,
  probe_pin=gpio22,
# fans
  fan_part_cooling_pin=gpio17,
  fan_toolhead_cooling_pin=gpio18,
  fan_controller_board_pin=gpio20,
# Bed heater
  heater_bed_heating_pin=gpio21,
  heater_bed_sensor_pin=gpio26,

# NEOPIXEL1 header
  NEOPIXEL_1=<GND>, NEOPIXEL_2=PA8, NEOPIXEL_3=null, # NEOPIXEL_3 = output of Neopixel PWR selector

# E0-STOP header (filament sensor input)
  E0_STOP_1=gpio16, E0_STOP_2=<GND>, E0_STOP_3=<5V>