Related Linear issue [[ https://linear.app/comm/issue/ENG-1295/clean-up-shell-scripts-in-codebase | here ]]. This is part of a set of diffs that will allow ShellCheck to be added to the CI. See inline comments for specific details of the ShellCheck error/warning output.
Not even sure if this script is used anywhere, since I searched the entire codebase and didn't find a usage of `setup.sh`. But it's blocking adding ShellCheck to the CI, so it was updated.