treewide: migrate to pluginRC for correct DAG order

The "new" DAG order is as follows:
- (luaConfigPre)
- globalsScript
- basic
- theme
- pluginConfigs
- extraPluginConfigs
- mappings
- (luaConfigPost)

modules/plugins/completion/nvim-cmp/config.nix

@@ -186,7 +186,7 @@ in {
 
     # TODO: alternative snippet engines to vsnip
     # https://github.com/hrsh7th/nvim-cmp/blob/main/doc/cmp.txt#L82
-    vim.luaConfigRC.completion = mkIf (cfg.type == "nvim-cmp") (dagPlacement ''
+    vim.pluginRC.completion = mkIf (cfg.type == "nvim-cmp") (dagPlacement ''
       local nvim_cmp_menu_map = function(entry, vim_item)
         -- name for each source
         vim_item.menu = ({