Defective keypad maybe? The RGB Keypad Base Micro Python demo.py file runs just fine?
Pico RGB Keypad Base support in CircuitPython - Support - Pimoroni Buccaneers
Pico RGB Keypad i2c pullup error - Discussion / Raspberry Pi - Pimoroni Buccaneers
EDIT: It looks like I have a defective RGB Keypad Base. I have two here, one had a defective LED, and the replacement that was sent for that defective one.
I just swapped the replacement for the original and the code in the other thread is working in Circuit Python with no i2c error message. Both of these bases run the Micro Python demo.py without error.
EDIT: Fixed my not working one. I soldered two 4.7 K pull up resistors on, one on GP4 to 3.3v and one on GP5 to 3.3v. Working now.