The fix: From O(N²) to efficient mappingThe fix: From O(N²) to efficient mapping

To resolve this performance issue, we contributed an upstream fix to Git that replaces the nested loops with a map data structure. Each reference is added to the map, which automatically ensures only a single copy of each reference is retained for processing.

This change dramatically enhances the performance of git bundle create and enables much better scalability in repositories with large reference counts. Benchmark testing on a repository with 10,000 references demonstrates a 6x performance improvement.