apply.sh unbound variable error

apply.sh exits with exit status 1

 ✓ All Done: resource Kustomization/sylva-system/sylva-units-status is ready!
./apply.sh: line 54: CHECK_TEST_UNITS: unbound variable

https://gitlab.com/sylva-projects/sylva-core/-/blob/main/tools/shell-lib/common.sh?ref_type=heads#L17

only sets CHECK_TEST_UNITS on the then branch