Fix commitsWithoutMergeCommits commits

commitsWithoutMergeCommits would just return just the first 100 commits.
Changelog: fixed
Signed-off-by: Lucas Zampieri <lzampier@redhat.com>

app/graphql/types/merge_request_type.rb

@@ -257,7 +257,7 @@ module Types
     end
 
     def commits_without_merge_commits
-      object.recent_commits.without_merge_commits
+      object.commits.without_merge_commits
     end
 
     def security_auto_fix