github/workflows/docker-tests.yml: use v4 checkout

v2 is deprecated.

Signed-off-by: Luis Chamberlain <[email protected]>

Author: mcgrof

.github/workflows/docker-tests.yml

@@ -46,7 +46,7 @@ jobs:
           fi
 
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Run make targets
         run: |