fix: skip the wide table check without a build

A missing page was a continue, so with no website/dist the test ran no assertion and reported ok.

tests/test_site_components.py

@@ -353,15 +353,24 @@ class WideTablesStackAndFiltersAreBuilt(unittest.TestCase):
     def test_every_wide_table_stacks(self):
         for page in ("emulators/duckstation", "gaps", "gaps-files-to-source", "emulators", "data",
                      "wiki/verification-modes"):
-            html = (DIST / page / "index.html")
-            if not html.is_file():
-                continue
-            for table in _tables(_read(html)):
+            for table in _tables(_built(page)):
                 if len(_headers(table)) < 4:
                     continue
                 with self.subTest(page=page, header=_headers(table)):
                     self.assertIn('data-rb-stack="true"', table.split(">", 1)[0])
 
+    def test_no_build_is_a_skip_not_a_pass(self):
+        """Every missing page was a `continue`: with no build the test ran no
+        assertion and still reported ok."""
+        from unittest import mock
+
+        module = sys.modules[__name__]
+        case = WideTablesStackAndFiltersAreBuilt("test_every_wide_table_stacks")
+        result = unittest.TestResult()
+        with mock.patch.object(module, "DIST", REPO_ROOT / "tmp" / "no-such-dist"):
+            case.run(result)
+        self.assertEqual(len(result.skipped), 1)
+
     def test_long_tables_get_their_labels_at_runtime(self):
         """Labels on every cell of a long stacked table were 122 KB of
         emulators/mame and took it over the 600,000-byte page budget."""