ci: update tidb cloud

Author: shhdgit

.github/workflows/production.yml

@@ -50,7 +50,7 @@ jobs:
           git submodule init
           git submodule update --remote
           cd docs
-          git checkout main
+          git checkout tidb-cloud
           cd ..
           echo "submodule_sha=$(git submodule status | awk '{print $1}' | sed -r 's/[+-]+//g')" >> $GITHUB_OUTPUT
           echo "submodule_status=$(git submodule status)" >> $GITHUB_OUTPUT