Tests: Add comments to the HTMLTokenizer regression test file

Author: https://github.com/MaxWipfli
Commit: a9a54914bf
Pull-request: https://github.com/SerenityOS/serenity/pull/8759
Issue: https://github.com/SerenityOS/serenity/issues/8757

Tests/LibWeb/TestHTMLTokenizer.cpp

@@ -193,5 +193,5 @@ TEST_CASE(regression)
     auto file_contents = file.value()->read_all();
     auto tokens = run_tokenizer(file_contents);
     u32 hash = hash_tokens(tokens);
-    EXPECT_EQ(hash, 1328591125u);
+    EXPECT_EQ(hash, 2891738465u);
 }