[chore] Fix link checker to allow empty links (open-telemetry#12055)

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#### Description
Fix an issue that `changelog` action will fail if there are no links
detected:
https://github.com/open-telemetry/opentelemetry-collector/actions/runs/12667603014/job/35301289365

Adding `failIfEmpty: false` to the action according to the doc:
https://github.com/lycheeverse/lychee-action/blob/master/README.md#passing-arguments
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.github/workflows/changelog.yml

@@ -82,3 +82,4 @@ jobs:
         uses: lycheeverse/lychee-action@f796c8b7d468feb9b8c0a46da3fac0af6874d374
         with:
           args: "--verbose --no-progress ./changelog_preview.md --config .github/lychee.toml"
+          failIfEmpty: false