Bug 15393

If tomllib doesn't exist and you run:

recipetool create -o /tmp https://github.com/mesonbuild/meson;rev=1.3.1

NOTE: Tasks Summary: Attempted 3 tasks of which 0 didn't need to be rerun and all succeeded.
ERROR: Neither 'tomllib' nor 'tomli' could be imported. Please use python3.11 or above or install tomli module
Traceback (most recent call last):
  File "/home/pokybuild/yocto-worker/oe-selftest-ubuntu/build/scripts/lib/recipetool/create_buildsys_python.py", line 814, in process
    import tomllib
ModuleNotFoundError: No module named 'tomllib'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/pokybuild/yocto-worker/oe-selftest-ubuntu/build/scripts/lib/recipetool/create_buildsys_python.py", line 817, in process
    import tomli as tomllib
ModuleNotFoundError: No module named 'tomli'
INFO: Scanning paths for packages & dependencies: .
INFO: Please add the following line for 'docs/markdown/legal.md' to a 'lib/recipetool/licenses.csv' and replace `Unknown` with the license:
000fe0dead3c0d575839e9d2bcfe2d5e,Unknown
INFO: Please add the following line for 'packaging/License.rtf' to a 'lib/recipetool/licenses.csv' and replace `Unknown` with the license:
074ef868ead2735d006e564c24e059c7,Unknown
INFO: Recipe /tmp/python3-meson_git.bb has been created; further editing may be required to make it fully functional

It fails, fine, but it says it did create a recipe when the file doesn't exist and exit code is zero.

We should fail if a file isn't written and not say one was when it was not.