[CI] Artifact task remove unnecessary build_hash

Author: picandocodigo

rake_tasks/elasticsearch_tasks.rake

@@ -83,9 +83,8 @@ namespace :elasticsearch do
       exit 1
     end
 
-    # Get the build hash if it hasn't been set from a running cluster
-    @build_hash ||= artifacts['version']['builds'].first.dig('projects', 'elasticsearch', 'commit_hash')
-
+    # Either find the artifacts for the exact same build hash from the current running cluster or
+    # use the first one from the list of builds:
     build_hash_artifact = artifacts['version']['builds'].find do |build|
       build.dig('projects', 'elasticsearch', 'commit_hash') == @build_hash
     end || artifacts['version']['builds'].first