fix: circle bg image in home page (#962)

Co-authored-by: tingzhao.ytz <[email protected]>

Author: yutingzhao1991

.dumi/theme/builtins/HomePage/components/Theme/index.module.less

@@ -26,8 +26,9 @@
     left: 80px;
     bottom: 60px;
     width: 486px;
-    height: 486px;
-    background-image: url(https://mdn.alipayobjects.com/huamei_mutawc/afts/img/A*vhNURbKgnA0AAAAAAAAAAAAADlrGAQ/original);
+    height: 386px;
+    background-image: url(https://mdn.alipayobjects.com/huamei_mutawc/afts/img/A*Wcc_S5HOjE8AAAAAAAAAAAAADlrGAQ/original);
+    background-repeat: no-repeat;
     background-size: contain;
   }