fix: week error in fuzzing scripts

[its403]

Issue:
In bash, when you use (( for arithmetic evaluation, numbers with leading zeros are interpreted as octal numbers. Since '9' isn't a valid octal digit, you get the error: value too great for base (error token is "09").

Fix:
This PR updates the script to force decimal interpretation of the week number using 10# in the arithmetic expression:
at_index=$(((10#$(date -u +%U)) % ${#fuzzing_scripts[@]}))

As you can see now, the correct script is being selected for week 9. I've also tested running fuzzing script on my fork in GitHub Actions.

https://github.com/its403/cve-bin-tool/actions/runs/13652954835/job/38165491473

[mastersans]

Looks good to me. It seems i need to take some bash lessons, but hey this one was some of my first contributions.

[terriko]

Thank you! I'll get this merged and then I'll re-run the fuzzer for this week.