Disable most documentation notifications on GitHub

Previously, the documentation comment on GitHub would be removed and
then recreated which creates notification emails and to some feels like
it's polluting their GitHub inbox.

Here, we change this behavior so that only the initial build of the
documentation causes such a notification. Further updates to the
documentation, do update the links in the comment but do not trigger a
notification.

This is meant as an alternative to sagemath#37387. See sagemath#37739 for futher ideas
about a smarter behavior here.

.github/PULL_REQUEST_TEMPLATE.md

@@ -15,7 +15,7 @@
 - [ ] The description explains in detail what this PR is about.
 - [ ] I have linked a relevant issue or discussion.
 - [ ] I have created tests covering the changes.
-- [ ] I have updated the documentation accordingly.
+- [ ] I have updated the documentation and checked the generated documentation. <!-- You do not need to build the documentation locally. A bot is recreating the documentation whenever there is a change to this PR and will maintain a link to the latest preview once it's ready. -->
 
 ### :hourglass: Dependencies
 

.github/workflows/doc-publish.yml

@@ -70,7 +70,7 @@ jobs:
         with:
           number: ${{ steps.source-run-info.outputs.pullRequestNumber }}
           header: preview-comment
-          recreate: true
+          recreate: false
           message: |
             [Documentation preview for this PR](${{ steps.deploy-netlify.outputs.NETLIFY_URL }}/html/en) (built with commit ${{ steps.source-run-info.outputs.sourceHeadSha }}; [changes](${{ steps.deploy-netlify.outputs.NETLIFY_URL }}/CHANGES.html)) is ready! :tada: