fix: state alias, test and game versions from code

An alias carries the version of the profile it aliases (version_basis
kind alias): mednafen_saturn and mednafen_vb read v1.32.1 and v1.31.0,
the mupen64plus_next builds 2.6.0, flycast_gles2 the flycast tag form.
The libretro-samples test cores without a pin take the commit their
profiled_date names and read library_version there.

emulators/mupen64plus_next_develop.yml

@@ -2,7 +2,10 @@ emulator: "Mupen64Plus-Next Develop"
 type: alias
 alias_of: "mupen64plus_next"
 profiled_date: "2026-03-24"
-core_version: "2.8"
+core_version: "2.6.0"
+version_basis:
+  kind: alias
+  of: "mupen64plus_next"
 display_name: "Nintendo - Nintendo 64 (Mupen64Plus-Next Develop)"
 cores:
   - mupen64plus_next_develop