Update deploy-docs.yml

Signed-off-by: Ryan Baxter <ryan.baxter@broadcom.com>

Author: ryanjbaxter

.github/workflows/deploy-docs.yml

@@ -16,7 +16,7 @@ jobs:
     # if: github.repository_owner == 'spring-cloud'
     steps:
       - name: Checkout
-        uses: actions/checkout@v7
+        uses: "actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1" # v7.0.1
         with:
           ref: docs-build
           fetch-depth: 1