chore: drop label comments across scripts

CommentsSayWhy read three scripts while 22 comments in 13 other files
named the next statement. They are removed or replaced by the reason,
and the test reads every tracked script and install.py.

scripts/scraper/mame_parser.py

@@ -372,13 +372,12 @@ def _parse_rom_entries(block: str) -> list[dict]:
         ("rom_load", _ROM_LOAD),
     ]
 
-    # Collect all matches with their positions
     events: list[tuple[int, str, re.Match]] = []
     for tag, pat in token_patterns:
         for m in pat.finditer(block):
             events.append((m.start(), tag, m))
 
-    # Sort by position in block
+    # Walked in source order: a ROM_LOAD belongs to the last ROM_REGION above it.
     events.sort(key=lambda e: e[0])
 
     for _pos, tag, m in events: