File _service of Package webm

<services>
  <service name="tar_scm">
    <param name="filename">webm</param>
    <param name="scm">git</param>
    <param name="url">https://github.com/webmproject/libwebm</param>
    <param name='revision'>main</param>
    <param name='versionformat'>1.0.0.31+git.%ci~%h</param>
    <param name="changesgenerate">enable</param>
  </service>
  <service name="recompress">
    <param name="file">*tar</param>
    <param name="compression">xz</param>
  </service>
  <service name="set_version"/>
</services>