fix: Fix is_in_team being false when team arg is empty when it should be opposite

Author: BlayTheNinth

common/src/main/java/net/blay09/mods/shogi/common/effect/condition/player/IsInTeam.java

@@ -31,7 +31,7 @@ public static MapCodec<IsInTeam> mapCodec(ShogiScope scope) {
         }
 
         final var expectedTeam = teamResult.mapLeft(Coercion.STRING).orThrow();
-        return Either.left(isInTeam(context.requirePlayer().getTeam(), expectedTeam));
+        return Either.left(expectedTeam.isEmpty() || isInTeam(context.requirePlayer().getTeam(), expectedTeam));
     }
 
     static boolean isInTeam(@Nullable PlayerTeam playerTeam, String expectedTeam) {