Update release instructions to mention GitHub Actions

RELEASING.rst

@@ -52,17 +52,14 @@ PGP keys set up. Then, push the tag to GitHub, e.g.::
 
     git push upstream v0.1
 
-and the build should happen automatically on Azure pipelines. You can
+and the build should happen automatically on GitHub Actions pipelines. You can
 follow the progress of the build here:
 
-https://dev.azure.com/liberfa/pyerfa/_build
+https://github.com/liberfa/pyerfa/actions/workflows/publish.yml
 
 If there are any failures, you can always delete the tag, fix the
 issues, tag the release again, and push the tag to GitHub.
 
-See the `OpenAstronomy Azure Pipelines Templates Documentation <https://openastronomy-azure-pipelines.readthedocs.io/en/latest/publish.html>`_
-for more details about the Azure Pipelines set-up.
-
 Finally, for completeness, update the ``Releases`` section on the main
 github page.  Click on the new tag you just made, then ``edit tag``,
 then insert ``vx.y.z`` for the version, and in the description write