Check if a commit belongs to pipeline before trying to expire cache

app/services/ci/expire_pipeline_cache_service.rb

@@ -7,7 +7,7 @@ module Ci
       store = Gitlab::EtagCaching::Store.new
 
       store.touch(project_pipelines_path)
-      store.touch(commit_pipelines_path)
+      store.touch(commit_pipelines_path) if pipeline.commit
       store.touch(new_merge_request_pipelines_path)
       merge_requests_pipelines_paths.each { |path| store.touch(path) }
     end