Remove unnecessary assembly references from build script

Only reference game-specific DLLs, let Mono provide system libraries

build.sh

@@ -5,10 +5,6 @@ GAME_DIR="${GAME_DIR:-$HOME/.local/share/7DaysToDie}"
 
 mcs -target:library \
     -out:BotCommandMod.dll \
-    -r:"$GAME_DIR/7DaysToDie_Data/Managed/mscorlib.dll" \
-    -r:"$GAME_DIR/7DaysToDie_Data/Managed/netstandard.dll" \
-    -r:"$GAME_DIR/7DaysToDie_Data/Managed/System.dll" \
-    -r:"$GAME_DIR/7DaysToDie_Data/Managed/System.Core.dll" \
     -r:"$GAME_DIR/7DaysToDie_Data/Managed/Assembly-CSharp.dll" \
     -r:"$GAME_DIR/7DaysToDie_Data/Managed/UnityEngine.CoreModule.dll" \
     -r:"$GAME_DIR/7DaysToDie_Data/Managed/0Harmony.dll" \