fix: simplify boolean evaluation logic in ExpressionParser

Author: sharrlotte

src/main/java/mindustrytool/workflow/expressions/ExpressionParser.java

@@ -157,18 +157,10 @@ public Boolean evaluateAsBoolean(String expr, Map<String, Object> variables) {
             return (Boolean) result;
         }
 
-        if (result == null) {
-            return false;
-        }
-
         if (result instanceof String) {
             return Boolean.parseBoolean(result.toString());
         }
-
-        if (result instanceof Number) {
-            return ((Number) result).doubleValue() != 0;
-        }
-
+        
         throw new WorkflowError("Invalid boolean value: " + result.toString());
     }