Try setting user/email inside script

Author: hinerm

.github/build.sh

@@ -6,6 +6,8 @@
 # Push it to the gh-pages branch.
 git clone --depth=1 --branch=gh-pages git@github.com:scijava/status.scijava.org site &&
 mv -f index-new.html site/index.html &&
+git config --global user.name github-actions &&
+git config --global user.email github-actions@github.com &&
 cd site &&
 if git diff --quiet index.html
 then

.github/workflows/build.yml

@@ -16,7 +16,4 @@ jobs:
            ssh-private-key: ${{ secrets.SSH_PRIVATE_KEY }}
 
       - name: Execute the build
-        run: |
-          git config user.name github-actions
-          git config user.email github-actions@github.com
-          .github/build.sh
+        run: .github/build.sh