Replaced iterative `git log` calls (N+1 problem) with a single `git for-each-ref` command to fetch branch metadata.
This reduces execution time from O(N) to O(1) regarding subprocess calls.
- Removed `get_prs_via_git` and `get_branch_info`
- Added `get_branches_info_git` using `%(ahead-behind:base)` format
- Updated `main` loop to use pre-calculated data
- Measured ~3.5x speedup on current repo state
Co-authored-by: Mouy-leng <199350297+Mouy-leng@users.noreply.github.com>
