🔥 clean: remove unuse less (#6214)

src/components/NoticeIcon/NoticeList.less

@@ -19,7 +19,7 @@
 
     .avatar {
       margin-top: 4px;
-      background: #fff;
+      background: @component-background;
     }
     .iconElement {
       font-size: 32px;

src/utils/utils.less

@@ -1,37 +1,3 @@
-.textOverflow() {
-  overflow: hidden;
-  white-space: nowrap;
-  text-overflow: ellipsis;
-  word-break: break-all;
-}
-
-.textOverflowMulti(@line: 3, @bg: #fff) {
-  position: relative;
-  max-height: @line * 1.5em;
-  margin-right: -1em;
-  padding-right: 1em;
-  overflow: hidden;
-  line-height: 1.5em;
-  text-align: justify;
-  &::before {
-    position: absolute;
-    right: 14px;
-    bottom: 0;
-    padding: 0 1px;
-    background: @bg;
-    content: '...';
-  }
-  &::after {
-    position: absolute;
-    right: 14px;
-    width: 1em;
-    height: 1em;
-    margin-top: 0.2em;
-    background: white;
-    content: '';
-  }
-}
-
 // mixins for clearfix
 // ------------------------
 .clearfix() {