Ansible: `build gn` task broken

[richardlau]

I'm rebuilding rhel9 ppc64_le and s390x machines and Ansible is failing to build gn:

e.g.

TASK [gn : build gn] ********************************************************************************************************************************************************************************************
fatal: [test-ibm-rhel8-s390x-4]: FAILED! => {"changed": true, "cmd": "python3 build/gen.py && . /opt/rh/gcc-toolset-11/enable && /home/iojs/build-tools/ninja -C out && out/gn_unittests\n", "delta": "0:00:00.038250", "end": "2025-04-02 08:59:48.858060", "msg": "non-zero return code", "rc": 1, "start": "2025-04-02 08:59:48.819810", "stderr": "Traceback (most recent call last):\n  File \"build/gen.py\", line 960, in <module>\n    sys.exit(main(sys.argv[1:]))\n  File \"build/gen.py\", line 228, in main\n    WriteGNNinja(os.path.join(out_dir, 'build.ninja'), platform, host, options, args_list)\n  File \"build/gen.py\", line 494, in WriteGNNinja\n    if is_gcc(cxx):\n  File \"build/gen.py\", line 239, in is_gcc\n    capture_output=True)\n  File \"/usr/lib64/python3.6/subprocess.py\", line 423, in run\n    with Popen(*popenargs, **kwargs) as process:\nTypeError: __init__() got an unexpected keyword argument 'text'", "stderr_lines": ["Traceback (most recent call last):", "  File \"build/gen.py\", line 960, in <module>", "    sys.exit(main(sys.argv[1:]))", "  File \"build/gen.py\", line 228, in main", "    WriteGNNinja(os.path.join(out_dir, 'build.ninja'), platform, host, options, args_list)", "  File \"build/gen.py\", line 494, in WriteGNNinja", "    if is_gcc(cxx):", "  File \"build/gen.py\", line 239, in is_gcc", "    capture_output=True)", "  File \"/usr/lib64/python3.6/subprocess.py\", line 423, in run", "    with Popen(*popenargs, **kwargs) as process:", "TypeError: __init__() got an unexpected keyword argument 'text'"], "stdout": "", "stdout_lines": []}

I think this is a sequencing issue after #3746 -- we need to install ninja-build before the gn role (as written the gn role is being run as a dependency of build-test-v8 so before build-test-v8 attempts to install ninja-build).