fix: drop the mac.rom alias from basiliskii

Basilisk II opens rom_path or ROM_FILE_NAME "ROM" (BasiliskII/src/Unix/main_unix.cpp:109, 685) and never mac.rom. RetroPie's basilisk.sh:56 passes $romdir/macintosh/mac.rom with --rom, recorded under launchers: in retropie.yml.

emulators/basiliskii.yml

@@ -65,7 +65,6 @@ notes: |
 
 files:
   - name: ROM
-    aliases: [mac.rom]
     required: true
     min_size: 524288
     max_size: 1048576