fix: 修复 PSelect 组件的 invalid 属性逻辑

src/__fk-inputs__/inputs/p-select.tsx

@@ -77,7 +77,7 @@ const SchemaComponent = defineComponent(
           ref={primevueSelectInstance}
           labelId={formkitContext.id}
           fluid
-          invalid={formkitContext.state.invalid || valueSlot.value !== undefined}
+          invalid={formkitContext.state.invalid}
           disabled={!!formkitContext.disabled}
           loading={loading.value}
           options={p_options.value}