antdv下拉框展开选项到刚好到浏览器底部触发闪烁，会回弹一下

关闭下拉框的动画样式即可解决

.ant-select-dropdown.slide-up-appear.slide-up-appear-active.ant-select-dropdown-placement-bottomLeft, .ant-select-dropdown.slide-up-enter.slide-up-enter-active.ant-select-dropdown-placement-bottomLeft {

  -webkit-animation-name: unset;

  animation-name: unset;

  -webkit-animation-duration: .05s;

  animation-duration: .05s;

}

.ant-select-dropdown.slide-up-appear.slide-up-appear-active.ant-select-dropdown-placement-topLeft, .ant-select-dropdown.slide-up-enter.slide-up-enter-active.ant-select-dropdown-placement-topLeft {

  -webkit-animation-name: unset;

  animation-name: unset;

  -webkit-animation-duration: .05s;

  animation-duration: .05s;

}

.ant-select-dropdown.slide-up-leave.slide-up-leave-active.ant-select-dropdown-placement-bottomLeft {

  -webkit-animation-name: unset;

  animation-name: unset;

  -webkit-animation-duration: .05s;

  animation-duration: .05s;

}

.ant-select-dropdown.slide-up-leave.slide-up-leave-active.ant-select-dropdown-placement-topLeft {

  -webkit-animation-name: unset;

  animation-name: unset;

  -webkit-animation-duration: .05s;

  animation-duration: .05s;

}