Disable concurrent_skipping for skip-duplicate-actions

From https://github.com/fkirc/skip-duplicate-actions?tab=readme-ov-file#concurrent_skipping

> Skip a workflow run if the same workflow is already running

but it does not seem reliable, for example, this workflow run
https://github.com/puma/puma/actions/runs/9386209788
looks 100% green but that is because everything was skipped

https://github.com/fkirc/skip-duplicate-actions/issues has many reports
about problems with `concurrent_skipping`

celerity/celerity-runtime#148 is an example of
another project disabling it.

[ci skip]

.github/workflows/skip_duplicate_workflow_runs.yml

@@ -28,5 +28,5 @@ jobs:
         with:
           paths_ignore: '["**.md"]'
           paths: ${{ inputs.paths }}
-          concurrent_skipping: 'same_content_newer' # skip newer runs with same content
+          concurrent_skipping: 'never' # this feature has bugs
           skip_after_successful_duplicate: 'true'