MRE of a Neovim config using Mason and Null-ls to format files using prettierd

init.lua

local install_path = vim.fn.stdpath 'data' .. '/site/pack/packer/start/packer.nvim'
local is_bootstrap = false
if vim.fn.empty(vim.fn.glob(install_path)) > 0 then
  is_bootstrap = true
  vim.fn.system { 'git', 'clone', '--depth', '1', 'https://github.com/wbthomason/packer.nvim', install_path }
  vim.cmd [[packadd packer.nvim]]
end

require('packer').startup(function(use)
  use 'wbthomason/packer.nvim'
  use {
    'neovim/nvim-lspconfig',
    requires = {
      'williamboman/mason.nvim',
      'williamboman/mason-lspconfig.nvim',
    },
  }
  use {
    'jose-elias-alvarez/null-ls.nvim',
    requires = 'nvim-lua/plenary.nvim'
  }
  if is_bootstrap then
    require('packer').sync()
  end
end)

if is_bootstrap then
  return
end

local on_attach = function(_, bufnr)
  vim.api.nvim_buf_create_user_command(bufnr, 'Format', function(_)
    vim.lsp.buf.format({
      bufnr = bufnr,
      filter = function(client)
    	  return client.name == "null-ls"
      end
    })
    print("File formatted")
  end, { desc = 'Format current buffer with LSP' })
end

local servers = {
  tsserver = {},
}

require('mason').setup()
local mason_lspconfig = require 'mason-lspconfig'

mason_lspconfig.setup {
  ensure_installed = vim.tbl_keys(servers),
}

mason_lspconfig.setup_handlers {
  function(server_name)
    require('lspconfig')[server_name].setup {
      capabilities = capabilities,
      on_attach = on_attach,
      settings = servers[server_name],
    }
  end,
}

local null_ls = require("null-ls")
null_ls.setup({
  sources = {
    null_ls.builtins.formatting.prettierd,
  },
})
vim.cmd([[colo slate]])

Is there a way to undo what this script has done ?

Now I have this message everytime I open nvim

[lspconfig] requires neovim 0.8 or later. Detected neovim version: 0.7.2

Is there a way to undo what this script has done ?

Now I have this message everytime I open nvim

[lspconfig] requires neovim 0.8 or later. Detected neovim version: 0.7.2

update your neovim