gh-36661: .github/workflows/doc-build.yml: Fix live doc building

    
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 Fixes the problem seen in

https://github.com/sagemath/sage/actions/runs/6761900181/job/18377280664

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URL: #36661
Reported by: Kwankyu Lee
Reviewer(s): Kwankyu Lee, Matthias Köppe

.github/workflows/doc-build.yml

@@ -182,7 +182,6 @@ jobs:
           echo '</body>' >> ./docs/CHANGES.html
           echo '</html>' >>./docs/CHANGES.html
           rm ./docs/diff.txt ./docs/diff.html
-          (cd /sage/local/share/doc/sage/html && git reset --hard HEAD)
           # For some reason the deploy step below cannot find /sage/...
           # So copy everything from there to local folder
           # We also need to replace the symlinks because netlify is not following them