Running `python-inspector` gives `KeyError: 'dictionary is empty'`

This comes from [ORT](https://github.com/oss-review-toolkit/ort) running

python-inspector --python-version 311 --operating-system linux --json-pdt /tmp/ort-PythonInspector1958014688763264125/python-inspector6282585536190674410.json --analyze-setup-py-insecurely --requirement /var/jenkins_home/workspace/ORT@tmp/project/source/anonymizer_module/test_requirements.txt --setup-py /var/jenkins_home/workspace/ORT@tmp/project/source/anonymizer_module/setup.py --verbose

on https://github.com/nordic-institute/X-Road-Metrics/blob/ce07b95f1fc6fe8236a1d4f6e3bed95b84d313a4/anonymizer_module/test_requirements.txt, see

```
PIP failed to resolve dependencies for path 'anonymizer_module/test_requirements.txt': IOException: Running 'python-inspector --python-version 311 --operating-system linux --json-pdt /tmp/ort-PythonInspector1958014688763264125/python-inspector6282585536190674410.json --analyze-setup-py-insecurely --requirement /var/jenkins_home/workspace/ORT@tmp/project/source/anonymizer_module/test_requirements.txt --setup-py /var/jenkins_home/workspace/ORT@tmp/project/source/anonymizer_module/setup.py --verbose' in '/var/jenkins_home/workspace/ORT@tmp/project/source/anonymizer_module' failed with exit code 1:
Traceback (most recent call last):
File "/usr/local/lib/python3.10/dist-packages/resolvelib/resolvers.py", line 316, in _backjump
name, candidate = broken_state.mapping.popitem()
KeyError: 'dictionary is empty'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/lib/python3.10/dist-packages/python_inspector/resolve_cli.py", line 253, in resolve_dependencies
resolution_result: Dict = resolver_api(
File "/usr/local/lib/python3.10/dist-packages/python_inspector/api.py", line 279, in resolve_dependencies
resolution, purls = resolve(
File "/usr/local/lib/python3.10/dist-packages/python_inspector/api.py", line 341, in resolve
resolved_dependencies, packages = get_resolved_dependencies(
File "/usr/local/lib/python3.10/dist-packages/python_inspector/api.py", line 379, in get_resolved_dependencies
resolver_results = resolver.resolve(requirements=requirements, max_rounds=max_rounds)
File "/usr/local/lib/python3.10/dist-packages/resolvelib/resolvers.py", line 546, in resolve
state = resolution.resolve(requirements, max_rounds=max_rounds)
File "/usr/local/lib/python3.10/dist-packages/resolvelib/resolvers.py", line 434, in resolve
success = self._backjump(causes)
File "/usr/local/lib/python3.10/dist-packages/resolvelib/resolvers.py", line 318, in _backjump
raise ResolutionImpossible(causes)
resolvelib.resolvers.ResolutionImpossible: [RequirementInformation(requirement=, parent=None), RequirementInformation(requirement==3.11')>, parent=Candidate(name='pymongo-stubs', version=, extras=set())), RequirementInformation(requirement=, parent=None), RequirementInformation(requirement==3.11')>, parent=Candidate(name='pymongo-stubs', version=, extras=set()))]
```