chore: align two tests with the merged lock flow

The lock refusal moved to stderr and pipeline labels lost their /8 in
two branches that met at merge.

tests/test_artifact_lock.py

@@ -138,7 +138,7 @@ class PackLockCliTest(unittest.TestCase):
             except subprocess.TimeoutExpired:
                 self.fail("generate_pack waited on the data tree instead of refusing")
         self.assertEqual(proc.returncode, 1, proc.stdout + proc.stderr)
-        self.assertIn("is in use by another run", proc.stdout)
+        self.assertIn("is in use by another run", proc.stderr)
 
     def test_every_writing_mode_refuses_a_locked_output(self):
         """Two of seven modes took the lock, and five wrote straight into it.

tests/test_audit_regressions.py

@@ -6115,8 +6115,12 @@ class SkipPacksHelpSaysWhatRuns(unittest.TestCase):
         self.assertIn("Steps 7 and 8 still rewrite README.md and docs/", text)
 
     def test_every_step_it_names_is_one_it_skips(self):
+        sys.path.insert(0, str(ROOT / "scripts"))
+        import pipeline
+
         source = (ROOT / "scripts" / "pipeline.py").read_text(encoding="utf-8")
-        skipped = set(re.findall(r"--- (\w+)/8 [^\n]*SKIPPED \(--skip-packs\)", source))
+        keys = re.findall(r'skip_notice\("(\w+)", "--skip-packs"\)', source)
+        skipped = {pipeline.step_number(key) for key in keys}
         self.assertEqual(skipped, {"4", "4b", "4c", "6"})