test: check pylint for new files before adding them to git

Author: nedbat

tox.ini

@@ -80,12 +80,12 @@ setenv =
 commands =
     python -m tabnanny {env:LINTABLE}
     python igor.py check_eol
-    check-manifest --ignore 'lab/*,perf/*,doc/sample_html/*,.treerc,.github*'
     # If 'build -q' becomes a thing (https://github.com/pypa/build/issues/188),
     # this can be simplifed:
     python igor.py quietly "python -m build"
     twine check dist/*
     python -m pylint --notes= {env:LINTABLE}
+    check-manifest --ignore 'lab/*,perf/*,doc/sample_html/*,.treerc,.github*'
 
 [gh-actions]
 python =