fix: give one native system id one slug

RetroDECK filed coco as tandy-coco and Dragon as dragon-32-64, MiSTer
filed COCO3 as tandy-coco and Recalbox kept its raw ids, so none of
them met xroar's coco, coco3 and dragon64 and its ROMs reached no
system. The scraper maps now agree and a test holds every shared
native id to one system.

scripts/scraper/emudeck_scraper.py

@@ -85,7 +85,7 @@ SYSTEM_SLUG_MAP = {
     "ps2": "sony-playstation-2",
     "ps3": "sony-playstation-3",
     "psp": "sony-psp",
-    "psvita": "sony-psvita",
+    "psvita": "sony-playstation-vita",
     "segacd": "sega-mega-cd",
     "megacd": "sega-mega-cd",
     "saturn": "sega-saturn",