Merge pull request #392 from OpenPrinting/dependabot/github_actions/redhat-plumbers-in-action/differential-shellcheck-5.5.3

Bump redhat-plumbers-in-action/differential-shellcheck from 5.5.1 to 5.5.3

Author: zdohnal

.github/workflows/differential-shellcheck.yml

@@ -21,6 +21,6 @@ jobs:
           fetch-depth: 0
 
       - name: Differential ShellCheck
-        uses: redhat-plumbers-in-action/differential-shellcheck@5fa026e4797665181a0f7c6fa4a73c09348ae78c
+        uses: redhat-plumbers-in-action/differential-shellcheck@dd551ce780d8af741f8cd8bab6982667b906b457
         with:
           token: ${{ secrets.GITHUB_TOKEN }}