fix(builtin.builtin): schedule opening next picker

Without scheduling, lots of vim state will be related to the builtin
picker when the new picker is opened despite closing the builtin picker
first and then opening a new picker.

This impacts state like `vim.fn.mode()`. If the builtin picker was
closed in insert mode, the closing action _should_ put you back in
normal mode. But without scheduling, the next picker is opened before it
does. So doing `vim.fn.mode()` in the subsequent picker will tell you,
you're still in insert mode. Typically, when chaining pickers, you want
the pre-telescope state, making the transitions between pickers
seemless.

lua/telescope/builtin/__internal.lua

@@ -109,16 +109,18 @@ internal.builtin = function(opts)
           end
 
           actions.close(prompt_bufnr)
-          if string.match(selection.text, " : ") then
-            -- Call appropriate function from extensions
-            local split_string = vim.split(selection.text, " : ")
-            local ext = split_string[1]
-            local func = split_string[2]
-            require("telescope").extensions[ext][func](picker_opts)
-          else
-            -- Call appropriate telescope builtin
-            require("telescope.builtin")[selection.text](picker_opts)
-          end
+          vim.schedule(function()
+            if string.match(selection.text, " : ") then
+              -- Call appropriate function from extensions
+              local split_string = vim.split(selection.text, " : ")
+              local ext = split_string[1]
+              local func = split_string[2]
+              require("telescope").extensions[ext][func](picker_opts)
+            else
+              -- Call appropriate telescope builtin
+              require("telescope.builtin")[selection.text](picker_opts)
+            end
+          end)
         end)
         return true
       end,