build: Fix run_command() usage in newer meson

WARNING: You should add the boolean check kwarg to the run_command call.
         It currently defaults to false,
         but it will default to true in future releases of meson.
         See also: https://github.com/mesonbuild/meson/issues/9300

tests/meson.build

@@ -4,7 +4,7 @@ envs.set ('top_srcdir', meson.source_root())
 
 python3 = find_program('python3')
 unittest_inspector = find_program('unittest_inspector.py')
-r = run_command(unittest_inspector, files('integration-test.py'))
+r = run_command(unittest_inspector, files('integration-test.py'), check: true)
 unit_tests = r.stdout().strip().split('\n')
 
 foreach ut: unit_tests