.ci/retrofit-worktree.sh: Set git config globally

Author: Matthias Koeppe

.ci/retrofit-worktree.sh

@@ -12,6 +12,10 @@ export GIT_AUTHOR_EMAIL="ci-sage@example.com"
 export GIT_COMMITTER_NAME="$GIT_AUTHOR_NAME"
 export GIT_COMMITTER_EMAIL="$GIT_AUTHOR_EMAIL"
 
+# Set globally for other parts of the workflow
+git config --global user.name "$GIT_AUTHOR_NAME"
+git config --global user.email "$GIT_AUTHOR_EMAIL"
+
 set -ex
 
 # If actions/checkout downloaded our source tree using the GitHub REST API