snacks.nvim has built-in GitHub PR/issue pickers via gh CLI

Recent snacks.nvim (2.31+) has a snacks.gh module with needs_setup = false, so you do not need to add an enabled key. Just map Snacks.picker.gh_pr() and Snacks.picker.gh_issue(), with { state = "all" } for closed items. It shells out to the gh CLI, so add gh to the editor's runtime deps. Snacks.git.blame_line() shows the git log for the current line, not gitsigns-style commit info, and snacks draws no gutter change signs, so keep gitsigns for the signs if the user moves blame and git pickers over to snacks.