ci(changelog): Improve failure message for changelog verifier

Signed-off-by: Umarov Ismoiljon <hs.umarov21@gmail.com>

Author: umaarov

.github/WORKFLOW_TROUBLESHOOTING.md

@@ -16,3 +16,8 @@ jobs:
       - uses: dangoslen/changelog-enforcer@v3
         with:
           skipLabels: "autocut, skip-changelog"
+          changeIsMissingMessage: |
+            ❌ ERROR: No update to CHANGELOG.md found!
+            This project requires a changelog entry for every user-facing change.
+            Please add a note about your change to the 'Unreleased' section of the CHANGELOG.md file.
+            You can find the file here: https://github.com/opensearch-project/OpenSearch/blob/main/CHANGELOG.md

.github/workflows/changelog_verifier.yml

@@ -14,7 +14,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Use S3CrtClient for higher throughput while uploading files to S3 ([#18800](https://github.com/opensearch-project/OpenSearch/pull/18800))
 - Add a dynamic setting to change skip_cache_factor and min_frequency for querycache ([#18351](https://github.com/opensearch-project/OpenSearch/issues/18351))
 - Add overload constructor for Translog to accept Channel Factory as a parameter ([#18918](https://github.com/opensearch-project/OpenSearch/pull/18918))
-- Add a troubleshooting guide for CI/CD checks to help new contributors ([#12979](https://github.com/opensearch-project/OpenSearch/issues/12979))
 
 ### Changed
 - Add CompletionStage variants to methods in the Client Interface and default to ActionListener impl ([#18998](https://github.com/opensearch-project/OpenSearch/pull/18998))