Fixed error messages in other tests.

Author: KOLANICH

tests/functional/test_install.py

@@ -641,9 +641,9 @@ def test_editable_install__local_dir_no_setup_py(
 
     msg = result.stderr
     if deprecated_python:
-        assert 'File "setup.py" not found. ' in msg
+        assert 'File "setup.py" or "setup.cfg" not found. ' in msg
     else:
-        assert msg.startswith('ERROR: File "setup.py" not found. ')
+        assert msg.startswith('ERROR: File "setup.py" or "setup.cfg" not found. ')
     assert 'pyproject.toml' not in msg
 
 
@@ -663,9 +663,9 @@ def test_editable_install__local_dir_no_setup_py_with_pyproject(
 
     msg = result.stderr
     if deprecated_python:
-        assert 'File "setup.py" not found. ' in msg
+        assert 'File "setup.py" or "setup.cfg" not found. ' in msg
     else:
-        assert msg.startswith('ERROR: File "setup.py" not found. ')
+        assert msg.startswith('ERROR: File "setup.py" or "setup.cfg" not found. ')
     assert 'A "pyproject.toml" file was found' in msg