Update source and target branches to release-x.57.x

Author: jeff-bruemmer

.github/workflows/update-latest-docs.yml

@@ -10,8 +10,8 @@ jobs:
   update-docs:
     uses: ./.github/workflows/update-docs-base.yml
     with:
-      source_branch: "release-x.56.x"
-      target_branch: "release-x.56.x"
+      source_branch: "release-x.57.x"
+      target_branch: "release-x.57.x"
       annotation: "nightly"
       run_name: "Nightly docs build - latest"
     secrets: