Mount point directory is not hidden when a filesystem is mounted on it

[dhalbert]

Noted as a result of https://forums.adafruit.com/viewtopic.php?t=215933

Adafruit CircuitPython 9.2.1-54-g26283dcb02 on 2025-01-06; Adafruit Metro ESP32S3 with ESP32S3
>>> import sdcardio,storage,board,os
>>> os.listdir()
['.fseventsd', '.metadata_never_index', '.Trashes', '.Trash-1000', 'sd', 'settings.toml', 'lib', 'boot_out.txt',  'ble_uart_echo_client.py']
>>> sdcard = sdcardio.SDCard(board.SPI(), board.SD_CS)
>>> vfs = storage.VfsFat(sdcard)
>>> storage.mount(vfs,"/sd")
>>> os.listdir()
# Now there are two 'sd` entries.
['sd', '.fseventsd', '.metadata_never_index', '.Trashes', '.Trash-1000', 'sd', 'settings.toml', 'lib', 'boot_out.txt',  'ble_uart_echo_client.py']
# But in this filesystem, there is only one.
>>> os.listdir(".")
['.fseventsd', '.metadata_never_index', '.Trashes', '.Trash-1000', 'sd', 'settings.toml', 'lib', 'boot_out.txt',  'ble_uart_echo_client.py']
>>> 

[RetiredWizard]

This might be simpler to solve than the other VfsFat mount point issues, but just in case someone's digging around, I figured I'd link a couple possibly related issues #9045 and #8409

[dhalbert]

Though the extra listing is confusing, it does not seem to affect actual functionality.