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

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

tools/ci.sh

@@ -33,6 +33,7 @@ function ci_code_formatting_run {
 # code size
 
 function ci_code_size_setup {
+    sudo apt-get update
     sudo apt-get install gcc-multilib
     gcc --version
     ci_gcc_arm_setup