feat: rescrape retrobat at its pinned commit

The scraper read emulatorLauncher master on every run, so an extractor
change was diffed together with upstream's commits since the pin. It now
rereads the commit platforms/retrobat.yml pins. --revision master moves
it, and check_freshness and refresh_stale pass that through the
registry's rescrape_args.

The extractors also read master (f681f435): Kronos and YabaSanshiro
fall back to sega_101.bin then mpr-17933.bin when the chosen BIOS is
absent, Ymir writes a forced BIOS only under its override flag, and a
folder created below bios (Ymir's cdb) is a passes_path record. At the
pin the 187 records are unchanged.

scripts/scraper/base_scraper.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import inspect
 import json
 import re
 import sys
@@ -391,10 +392,16 @@ def scraper_cli(
     parser.add_argument("--dry-run", action="store_true", help="Show scraped data")
     parser.add_argument("--output", "-o", help="Output YAML file")
     parser.add_argument("--json", action="store_true", help="Output as JSON")
+    takes_revision = "revision" in inspect.signature(scraper_class).parameters
+    if takes_revision:
+        parser.add_argument(
+            "--revision",
+            help="Read this branch head or commit instead of the revision the platform file pins",
+        )
     args = parser.parse_args()
 
     try:
-        scraper = scraper_class()
+        scraper = scraper_class(revision=args.revision) if takes_revision else scraper_class()
         reqs = scraper.fetch_requirements()
     except (OSError, ValueError, RuntimeError) as e:
         _exit_on_scrape_error(e)