Fix curl command when we have prompt variable to resolve

When we have prompt to resolve, error is raised. The command is `:Rest curl yank` ```http ### Anything # @prompt lang The accepted language GET https://httpbin.io/anything/hello Accept-Language: {{lang}} ``` ``` Error executing Lua callback: ...careem/.local/share/nvim/lazy/nvim-nio/lua/nio/tasks.lua:193: Cannot call async function from non-async context stack traceback: [C]: in function 'error' ...careem/.local/share/nvim/lazy/nvim-nio/lua/nio/tasks.lua:193: in function 'input' .../share/nvim/lazy/rest.nvim/lua/rest-nvim/parser/init.lua:471: in function 'parse' ...cal/share/nvim/lazy/rest.nvim/lua/rest-nvim/commands.lua:238: in function 'impl' ...cal/share/nvim/lazy/rest.nvim/lua/rest-nvim/commands.lua:309: in function <...cal/share/nvim/lazy/rest.nvim/lua/rest-nvim/commands.lua:297> ``` This fix the issue by wrapping it inside nio run function