tools/ci.sh: For ci_code_size_setup, update apt to install gcc-multilib.
tools/ci.sh: For ci_code_size_setup, update apt to install gcc-multilib.

Signed-off-by: Damien George <99e6b749acbfbe2a596df99e91d24d6e1fdbee00@micropython.org>

adafruit/circuitpython,adafruit/circuitpython,bvernoux/micropython,henriknelson/micropython,adafruit/circuitpython,bvernoux/micropython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,bvernoux/micropython,henriknelson/micropython,bvernoux/micropython,henriknelson/micropython,henriknelson/micropython,bvernoux/micropython,henriknelson/micropython