nvim: drop nvim-treesitter (archived, broken on 0.12), replace with mini.ai

dot_config/nvim/lua/plugins/treesitter-latex.lua

@@ -1,10 +1,2 @@
--- Ensure Treesitter knows about LaTeX (nabla benefits, and some plugins use it)
-return {
-  "nvim-treesitter/nvim-treesitter",
-  opts = function(_, opts)
-    opts.ensure_installed = opts.ensure_installed or {}
-    if type(opts.ensure_installed) == "table" then
-      if not vim.tbl_contains(opts.ensure_installed, "latex") then table.insert(opts.ensure_installed, "latex") end
-    end
-  end,
-}
+-- nvim-treesitter dropped; latex parser available via system package or tree-sitter-cli
+return {}