.gitlab-ci.yml: Fix compilation against cppTango main
Since cppTango/d7951ae2 (Replace TANGO_XXX_BASE with <Pkg_name>_ROOT, 2023-07-27) the BASE variables are not used anymore.
Since cppTango/d7951ae2 (Replace TANGO_XXX_BASE with <Pkg_name>_ROOT, 2023-07-27) the BASE variables are not used anymore.