fix(validation): Ensure If the terminal buffer is excluded.

[m4dd0c]

closes #1091

Problem

As I have explained, the current implementation of utils.buf_valid is not excluding terminal buffer, that is causing the token exceed problem.

Solution

Added a condition to check if the buffer is terminal_buffer using buftype.

--- Check if a buffer is valid
--- Check if the buffer is not a terminal
---@param bufnr number? The buffer number
---@return boolean
function M.buf_valid(bufnr)
  return bufnr
      and vim.api.nvim_buf_is_valid(bufnr)
      and vim.api.nvim_buf_is_loaded(bufnr)
      and vim.bo[bufnr].buftype ~= 'terminal'
    or false
end

[deathbeam]

Thanks. Dont think this is the best place for this check but it causes least conflicts with #1029 so for now its good enough.

@all-contributors add @m4dd0c for code

[allcontributors]

@deathbeam

I've put up a pull request to add @m4dd0c! 🎉