fix(CI): use -shellcheck="" to disable shellcheck in actionlint (PRI-1593)

-no-shellcheck is not a valid flag; -shellcheck="" disables shellcheck integration.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

.github/workflows/pr-validation.yaml

@@ -30,7 +30,7 @@ jobs:
           echo "$HOME/.local/bin" >> "$GITHUB_PATH"
 
       - name: Validate workflow YAML with actionlint
-        run: actionlint -no-shellcheck -color .github/workflows/*.yaml
+        run: actionlint -shellcheck="" -color .github/workflows/*.yaml
 
       - name: Install shellcheck
         run: |