README: rm Travis, add GHA CI badges

GHA CI is available since commit e5b1e63, while travis-ci.org is no more.

Signed-off-by: Kir Kolyshkin <[email protected]>
Acked-by: Tom Hromatka <[email protected]>
[PM: break up the long line a little]
Signed-off-by: Paul Moore <[email protected]>

Author: kolyshkin

README.md

@@ -2,7 +2,8 @@
 ===============================================================================
 https://github.com/seccomp/libseccomp-golang
 
-[![Build Status](https://img.shields.io/travis/seccomp/libseccomp-golang/main.svg)](https://travis-ci.org/seccomp/libseccomp-golang)
+[![validate](https://github.com/seccomp/libseccomp-golang/actions/workflows/validate.yml/badge.svg)](https://github.com/seccomp/libseccomp-golang/actions/workflows/validate.yml)
+[![test](https://github.com/seccomp/libseccomp-golang/actions/workflows/test.yml/badge.svg)](https://github.com/seccomp/libseccomp-golang/actions/workflows/test.yml)
 
 The libseccomp library provides an easy to use, platform independent, interface
 to the Linux Kernel's syscall filtering mechanism.  The libseccomp API is