[readme] remove build status because travis-ci is ceased since 2021

README.md

@@ -8,7 +8,6 @@
 [![GiteeStars](https://gitee.com/rtthread/rt-thread/badge/star.svg?theme=gvp)](https://gitee.com/rtthread/rt-thread/stargazers)
 [![GitHub](https://img.shields.io/github/license/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/blob/master/LICENSE)
 [![GitHub release](https://img.shields.io/github/release/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/releases)
-[![Build Status](https://travis-ci.org/RT-Thread/rt-thread.svg)](https://travis-ci.org/RT-Thread/rt-thread)
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/RT-Thread/rt-thread?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![GitHub pull-requests](https://img.shields.io/github/issues-pr/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/pulls)
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat)](https://github.com/RT-Thread/rt-thread/pulls)

README_de.md

@@ -8,7 +8,6 @@
 [![GiteeStars](https://gitee.com/rtthread/rt-thread/badge/star.svg?theme=gvp)](https://gitee.com/rtthread/rt-thread/stargazers)
 [![GitHub](https://img.shields.io/github/license/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/blob/master/LICENSE)
 [![GitHub release](https://img.shields.io/github/release/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/releases)
-[![Build Status](https://travis-ci.org/RT-Thread/rt-thread.svg)](https://travis-ci.org/RT-Thread/rt-thread)
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/RT-Thread/rt-thread?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![GitHub pull-requests](https://img.shields.io/github/issues-pr/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/pulls)
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat)](https://github.com/RT-Thread/rt-thread/pulls)

README_es.md

@@ -8,7 +8,6 @@
 [![GiteeStars](https://gitee.com/rtthread/rt-thread/badge/star.svg?theme=gvp)](https://gitee.com/rtthread/rt-thread/stargazers)
 [![GitHub](https://img.shields.io/github/license/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/blob/master/LICENSE)
 [![GitHub release](https://img.shields.io/github/release/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/releases)
-[![Build Status](https://travis-ci.org/RT-Thread/rt-thread.svg)](https://travis-ci.org/RT-Thread/rt-thread)
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/RT-Thread/rt-thread?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![GitHub pull-requests](https://img.shields.io/github/issues-pr/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/pulls)
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat)](https://github.com/RT-Thread/rt-thread/pulls)

README_zh.md

@@ -8,7 +8,6 @@
 [![GiteeStars](https://gitee.com/rtthread/rt-thread/badge/star.svg?theme=gvp)](https://gitee.com/rtthread/rt-thread/stargazers)
 [![GitHub](https://img.shields.io/github/license/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/blob/master/LICENSE)
 [![GitHub release](https://img.shields.io/github/release/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/releases)
-[![Build Status](https://travis-ci.org/RT-Thread/rt-thread.svg)](https://travis-ci.org/RT-Thread/rt-thread)
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/RT-Thread/rt-thread?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![GitHub pull-requests](https://img.shields.io/github/issues-pr/RT-Thread/rt-thread.svg)](https://github.com/RT-Thread/rt-thread/pulls)
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat)](https://github.com/RT-Thread/rt-thread/pulls)