Add `commit_raw` and `commit_as_raw` methods for creating commits without reference updates#2168

Byron merged 2 commits intomainGitoxideLabs/gitoxide:mainfrom

copilot/fix-01a02b99-91ef-4e27-b90f-19af7d0d252cGitoxideLabs/gitoxide:copilot/fix-01a02b99-91ef-4e27-b90f-19af7d0d252cCopy head branch name to clipboard