File _service of Package llvm21

<services>
  <service name="obs_scm">
    <param name="scm">git</param>
    <param name="url">https://github.com/llvm/llvm-project</param>
    <param name="revision">9ed1927</param>
    <param name="without-version">true</param>
  </service>
  <service name="tar" mode="buildtime">
    <param name="version">_none_</param>
  </service>
</services>