RP2040 busio.UART not freeing pin after detecting invalid pins

[dhalbert]

Adafruit CircuitPython 9.1.0-rc.0 on 2024-07-09; Adafruit Metro RP2040 with rp2040
>>> import board, busio
>>> u = busio.UART(board.SDA, board.SCL)
>>> u.deinit()
>>> u = busio.UART(board.SDA, board.SCL)
>>> u.deinit()
>>> u = busio.UART(board.SDA, board.A0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: Invalid pins
>>> u = busio.UART(board.SDA, board.A1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: SDA in use

SDA should not be in use.

User in discord encountered this when trying to run the Where's My UART code.