Use sh to run CI scripts
We can't assume that Bash is going to be installed, and should instead prepare to use sh.
The 17.0 major release is coming on May 16, 2024! This version brings many exciting improvements to GitLab, but also removes some deprecated features. We are introducing three breaking change windows during which we expect breaking changes to be deployed to GitLab.com. You can read more about it on our blogpost. The second breaking change window begins 2024-04-29 09:00 UTC and ends 2024-05-01 22:00 UTC.
We can't assume that Bash is going to be installed, and should instead prepare to use sh.