Apply suggestion from @jacobwinch

Co-authored-by: Jacob Winch <jacob.winch@guardian.co.uk>

Author: jorgeazevedo

.github/workflows/notification.yml

@@ -35,7 +35,7 @@ jobs:
 
       - run: corepack enable
 
-      - uses: actions/setup-node@v6
+      - uses: actions/setup-node@6044e13b5dc448c55e2357c09f80417699197238 #v6.2.0
         with:
           cache: yarn
           cache-dependency-path: cdk/yarn.lock