graphics/entangle: unbreak build with Meson 0.61.0

src/meson.build:42:5: ERROR: Function does not take positional arguments.
help/meson.build:23:6: ERROR: Program 'itstool' not found or not executable

PR: 260943
Reported by: antoine (via exp-run)
Regressed by: https://github.com/mesonbuild/meson/commit/61f2866a9fa1
Regressed by: https://github.com/mesonbuild/meson/commit/26c1869a142a