Setting up container giver warning about `--mode run`

[laraPPr]

This line,

software-layer-scripts/bot/build.sh

Line 212 in 62b8e33

COMMON_ARGS+=("--mode" "run")

, is currently triggering the following warning:

^[[33mNote: the behaviour of the run mode has changed.^[[0m

^[[33mPreviously, it mistakenly ran 'apptainer/singularity run', but it now runs 'apptainer/singularity exec' instead.^[[0m

^[[33mYou can silence this message by using --mode exec instead of --mode run.^[[0m

Should we updat this in https://github.com/EESSI/software-layer-scripts/blob/main/bot/build.sh.