fix: get_project_dependency_packages has to be called with dev=True (…

…packages are filtered by including/excluding groups of the root package)

src/poetry_plugin_export/exporter.py

@@ -109,6 +109,7 @@ def _export_requirements_txt(self, cwd: Path, output: IO | str) -> None:
         for dependency_package in self._poetry.locker.get_project_dependency_packages(
             project_requires=root_package.all_requires,
             project_python_marker=root_package.python_marker,
+            dev=True,
             extras=self._extras,
         ):
             line = ""