Regression tests for setup.cfg's options using the wrong section failing silently (#6335)

* Regression tests for #4272

Closes #4272. The problem was fixed during the migration from optparse
to argparse.

Co-authored-by: Daniël van Noord <[email protected]>

Author: Pierre-Sassoulas

tests/config/functional/setup_cfg/issue_4272/option_in_wrong_section.cfg

@@ -0,0 +1,7 @@
+# Test for the behaviour of https://github.com/PyCQA/pylint/issues/4272
+[pylint.NOTMASTER]
+load-plugins=pylint.extensions.bad_builtin
+[pylint.MASTER]
+persistent=no
+[pylint.DEPRECATED_BUILTINS]
+bad-functions=print,map

tests/config/functional/setup_cfg/issue_4272/option_in_wrong_section.result.json

@@ -0,0 +1,5 @@
+{
+  "load_plugins": ["pylint.extensions.bad_builtin"],
+  "persistent": false,
+  "bad_functions": ["print", "map"]
+}