ci: git user not set

Author: Mmx233

.github/workflows/sync-tag.yaml

@@ -23,21 +23,23 @@ jobs:
           latest_tag_name=$(wget -qO- -t1 -T2 "https://api.github.com/repos/tailscale/tailscale/releases/latest" | jq -r '.tag_name')
           if [ -z "$latest_tag_name" ]; then
             echo "fetch tag name failed"
-            echo "Tagged=false" >> $GITHUB_OUTPUT
+            echo "tagged=false" >> $GITHUB_OUTPUT
             exit 0
           fi
           latest_commit_hash=$(wget -qO- -t1 -T2 "https://api.github.com/repos/tailscale/tailscale/commits" | jq -r '.[0].sha')
           if [ -z "$latest_commit_hash" ]; then
             echo "fetch commit hash failed" 
-            echo "Tagged=false" >> $GITHUB_OUTPUT
+            echo "tagged=false" >> $GITHUB_OUTPUT
             exit 0
           fi
           version="${latest_tag_name}-${latest_commit_hash:0:7}"
           if git rev-parse "refs/tags/$version" >/dev/null 2>&1; then
             echo "tag exists"
-            echo "Tagged=false" >> $GITHUB_OUTPUT
+            echo "tagged=false" >> $GITHUB_OUTPUT
             exit 0
           fi
+          git config user.name "GitHub Actions"
+          git config user.email "github-actions@users.noreply.github.com"
           git tag -a $version -m "release $version"
           echo "tagged=true" >> $GITHUB_OUTPUT
           echo "commit-hash=${latest_commit_hash}" >> $GITHUB_OUTPUT