[tests] add support for skipping an extractor result test

test/results/sankaku.py

@@ -372,6 +372,7 @@ __tests__ = (
 {
     "#url"     : "https://sankaku.app/post/show/20758561",
     "#comment" : "empty tags (#1617)",
+    "#skip"    : "legacy, now unsupported, numerical post ID",
     "#category": ("booru", "sankaku", "post"),
     "#class"   : sankaku.SankakuPostExtractor,
     "#options" : {"tags": True},

test/test_results.py

@@ -106,6 +106,10 @@ class TestExtractorResults(unittest.TestCase):
         if len(result) <= 2:
             return  # only matching
 
+        skip = result.pop("#skip", False)
+        if skip:
+            return self._skipped.append((result["#url"], skip))
+
         if auth is None:
             auth = (cat in AUTH_REQUIRED)
         elif not auth: