Update doc/source/preparing_releases_and_hotfixes.rst

Author: RMeli

doc/source/preparing_releases_and_hotfixes.rst

@@ -170,7 +170,7 @@ For now, the UserGuide is released at the same time as the core library. If it's
       cd doc/source/scripts
       python -m pytest tests/snapshot/ --snapshot-update
 
-#. Define the ``GITHUB_TOKEN`` environment variable in with a GitHub personal access token that has the ``repo`` scope.
+#. Define the ``GITHUB_TOKEN`` environment variable with a GitHub personal access token that has the ``repo`` scope.
    The access token is used by the script at the next step.
 
 #. Make a Pull Request with a re-generated ``releases.md`` which contains a copy of the GitHub release notes. This can be generated by doing: