Merge pull request #411 from OpenPrinting/dependabot/github_actions/actions/checkout-6.0.0

Bump actions/checkout from 5.0.0 to 6.0.0

Author: zdohnal

.github/workflows/differential-shellcheck.yml

@@ -16,7 +16,7 @@ jobs:
 
     steps: 
       - name: Repository checkout
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
         with:
           fetch-depth: 0