Bump actions/checkout from 6 to 7 (#3254)

Author: dependabot[bot]

.github/workflows/deploy-docs.yml

@@ -16,7 +16,7 @@ jobs:
     # if: github.repository_owner == 'spring-cloud'
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
         with:
           ref: docs-build
           fetch-depth: 1