DOC: remove outdated page on git

We no longer do any local-merge-push-to-main work (it is forbidden via GH
access control rules).  All changes to both main and the bug-fix branches now
land via PR (including the bug-fix branch merge-up).

Author: tacaswell

doc/devel/coding_guide.rst

@@ -147,6 +147,8 @@ See also :ref:`contributing` for how to make a PR.
 Summary for pull request reviewers
 ==================================
 
+.. redirect-from:: /devel/maintainer_workflow
+
 .. note::
 
    * If you have commit rights, then you are trusted to use them.

doc/devel/index.rst

@@ -132,7 +132,6 @@ Contribution guides
       .. toctree::
          :maxdepth: 1
 
-         maintainer_workflow
          release_guide
          MEP/index