fix: a dual-mode name reaches its libretro profile

Batocera, Recalbox and RetroBat launch pcsx2 standalone and as LRPS2.
The name matched the standalone profile's key, so lrps2, which lists
pcsx2 among its cores, was left out and its files never reached those
packs. A name in dual_mode_cores now also resolves to the libretro
profiles that claim it.

scripts/common.py

@@ -2250,6 +2250,17 @@ def resolve_platform_cores(
             for c in core_set
             if (profile := preferred_profile(index, c)) is not None
         }
+        # A name the platform launches both ways designates its libretro
+        # build too. Batocera, Recalbox and RetroBat run pcsx2 standalone and
+        # as LRPS2, two profiles: the key match kept the standalone one and
+        # LRPS2's files never reached their packs.
+        result |= {
+            profile
+            for c in config.get("dual_mode_cores") or []
+            for profile in index.get(str(c), set())
+            if "libretro" in str(profiles[profile].get("type", ""))
+            and not profiles[profile].get("built_by")
+        }
         # Support "all_libretro" as a list element: combines all libretro
         # profiles with explicitly listed standalone cores (e.g. RetroDECK
         # ships RetroArch + standalone emulators)