Avoid warnings in build.

pyproject.toml

 [build-system]
-requires = ["setuptools", "setuptools-scm"]
+requires = ["setuptools"]
 build-backend = "setuptools.build_meta"
 
 [project]
@@ -38,7 +38,7 @@ offline = ["seaborn", "statsmodels", "matplotlib", "extra_data"]
 offline_analysis = "pes_to_spec.test.offline_analysis:main"
 
 [tool.setuptools]
-packages = ["pes_to_spec"]
+packages = ["pes_to_spec", "pes_to_spec.test"]
 include-package-data = true
 zip-safe = false