fix: association field in subtable triggering request when iteration variable with empty value (#6969)

packages/core/client/src/schema-settings/LinkageRules/bindLinkageRulesToFiled.ts

@@ -434,7 +434,7 @@ export async function replaceVariables(
 
   const waitForParsing = value.match(REGEX_OF_VARIABLE_IN_EXPRESSION)?.map(async (item) => {
     const { value: parsedValue } = await variables.parseVariable(item, localVariables, {
-      doNotRequest: item.includes('$nForm'),
+      doNotRequest: item.includes('$nForm') || item.includes('$iteration'),
     });
 
     // 在开头加 `_` 是为了保证 id 不能以数字开头，否则在解析表达式的时候（不是解析变量）会报错

packages/core/client/src/variables/VariablesProvider.tsx

@@ -357,7 +357,7 @@ function shouldToRequest(value, variableCtx: Record<string, any>, variablePath:
       return;
     }
 
-    result = value !== null && _.isEmpty(value);
+    result = _.isEmpty(value);
   });
 
   return result;