fix: Select width bug when searching (#32988)

* fix: select placeholder should take place when searching

close #27688

* fix snapshot

components/select/__tests__/__snapshots__/demo.test.js.snap

@@ -1711,7 +1711,6 @@ exports[`renders ./components/select/demo/responsive.md correctly 1`] = `
 exports[`renders ./components/select/demo/search.md correctly 1`] = `
 <div
   class="ant-select ant-select-single ant-select-show-arrow ant-select-show-search"
-  style="width:200px"
 >
   <div
     class="ant-select-selector"

components/select/demo/search.md

@@ -22,27 +22,16 @@ function onChange(value) {
   console.log(`selected ${value}`);
 }
 
-function onBlur() {
-  console.log('blur');
-}
-
-function onFocus() {
-  console.log('focus');
-}
-
 function onSearch(val) {
   console.log('search:', val);
 }
 
 ReactDOM.render(
   <Select
     showSearch
-    style={{ width: 200 }}
     placeholder="Select a person"
     optionFilterProp="children"
     onChange={onChange}
-    onFocus={onFocus}
-    onBlur={onBlur}
     onSearch={onSearch}
     filterOption={(input, option) =>
       option.children.toLowerCase().indexOf(input.toLowerCase()) >= 0

components/select/style/single.less

@@ -40,6 +40,7 @@
     }
 
     .@{select-prefix-cls}-selection-placeholder {
+      transition: none;
       pointer-events: none;
     }