fix: fix space duplicated key (#7048)

Author: cc-hearts

Diff for: components/space/index.tsx

@@ -107,7 +107,10 @@ const Space = defineComponent({
           style={[style.value, attrs.style as CSSProperties]}
         >
           {items.map((child, index) => {
-            const originIndex = children.indexOf(child);
+            let originIndex = children.indexOf(child);
+            if (originIndex === -1) {
+              originIndex = `$$space-${index}`;
+            }
             let itemStyle: CSSProperties = {};
             if (!supportFlexGap.value) {
               if (direction === 'vertical') {