Slow Linting/High CPU for Elixir Files

## Information

**VIM version**

NVIM v0.5.0
Build type: Release

Operating System: macOS 11.4

## What went wrong

~~For some reason, I can't seem to get ALE to auto-complete anything in Elixir files. This includes both elixir-ls autocompletion, as well as the standard language-agnostic word auto-completion. I've tried running `:ALEInfo`, and nothing sticks out to me. I also made sure let `g:ale_completion_enabled = 1` was called first thing in my configuration files before anything was loaded. I made sure to enable all of the Elixir linters that were disabled by default.~~

I can confirm that ALE auto-completion is now working. However, there's a delay before it starts working.

My autocompletion works fine in other languages like JavaScript and Ruby. Language servers also seem to work fine in those languages.

## Reproducing the bug

Create a new empty Elixir file: `:tabe ~/Desktop/example.ex`. Then paste the following into the file:

``` elixir
defmodule Banana do
def banana do
"banana"
end
end
```

At the end of this file, start typing the following:

```
IO.puts Banana.banana()
```

ALE should offer to autocomplete the module and filename, but nothing happens.

### :ALEInfo

```
Current Filetype: elixir
Available Linters: ['credo', 'dialyxir', 'dogma', 'elixir-ls', 'mix']
Enabled Linters: ['credo', 'dialyxir', 'dogma', 'elixir-ls', 'mix']
Ignored Linters: []
Suggested Fixers:
'mix_format' - Apply mix format to a file.
'remove_trailing_lines' - Remove all blank lines at the end of a file.
'trim_whitespace' - Remove all trailing whitespace characters at the end of every line.
Linter Variables:

let g:ale_elixir_elixir_ls_config = {}
let g:ale_elixir_elixir_ls_release = '/usr/local/Cellar/elixir-ls'
Global Variables:

let g:ale_cache_executable_check_failures = v:null
let g:ale_change_sign_column_color = 0
let g:ale_command_wrapper = ''
let g:ale_completion_delay = 100
let g:ale_completion_enabled = 1
let g:ale_completion_max_suggestions = 50
let g:ale_disable_lsp = 0
let g:ale_echo_cursor = 1
let g:ale_echo_msg_error_str = 'Error'
let g:ale_echo_msg_format = '%code: %%s'
let g:ale_echo_msg_info_str = 'Info'
let g:ale_echo_msg_warning_str = 'Warning'
let g:ale_enabled = 1
let g:ale_fix_on_save = 1
let g:ale_fixers = {'elixir': ['mix_format'], 'javascriptreact': ['eslint'], 'ruby': ['rubocop'], 'javascript': ['eslint']}
let g:ale_history_enabled = 1
let g:ale_history_log_output = 1
let g:ale_keep_list_window_open = 0
let g:ale_lint_delay = 200
let g:ale_lint_on_enter = 1
let g:ale_lint_on_filetype_changed = 1
let g:ale_lint_on_insert_leave = 1
let g:ale_lint_on_save = 1
let g:ale_lint_on_text_changed = 'normal'
let g:ale_linter_aliases = {}
let g:ale_linters = {'elixir': ['credo', 'dialyxir', 'dogma', 'elixir-ls', 'mix']}
let g:ale_linters_explicit = 0
let g:ale_linters_ignore = {'javascriptreact': ['tsserver'], 'javascript': ['tsserver']}
let g:ale_list_vertical = 0
let g:ale_list_window_size = 10
let g:ale_loclist_msg_format = '%code: %%s'
let g:ale_lsp_root = {}
let g:ale_max_buffer_history_size = 20
let g:ale_max_signs = -1
let g:ale_maximum_file_size = v:null
let g:ale_open_list = 0
let g:ale_pattern_options = v:null
let g:ale_pattern_options_enabled = v:null
let g:ale_set_balloons = 0
let g:ale_set_highlights = 1
let g:ale_set_loclist = 1
let g:ale_set_quickfix = 0
let g:ale_set_signs = 1
let g:ale_sign_column_always = 0
let g:ale_sign_error = '😦'
let g:ale_sign_info = '😡'
let g:ale_sign_offset = 1000000
let g:ale_sign_style_error = '😦'
let g:ale_sign_style_warning = '😡'
let g:ale_sign_warning = '😡'
let g:ale_sign_highlight_linenrs = 0
let g:ale_statusline_format = v:null
let g:ale_type_map = {}
let g:ale_use_global_executables = v:null
let g:ale_virtualtext_cursor = 0
let g:ale_warn_about_trailing_blank_lines = 1
let g:ale_warn_about_trailing_whitespace = 1
Command History:

(executable check - success) mix
(finished - exit code 1) ['/bin/zsh', '-c', 'cd ''.'' && mix help credo && mix credo suggest --format=flycheck --read-from-stdin ''/Users/landon/Desktop/example.ex'' < ''/var/folders/mt/4fyz36kj69l0j5fffrwlsvdh0000gn/T/nvimyUeVyq/4/example.ex''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', 'cd ''.'' && mix help dialyzer && mix dialyzer < ''/var/folders/mt/4fyz36kj69l0j5fffrwlsvdh0000gn/T/nvimyUeVyq/5/example.ex''']

<<>>

(executable check - success) /usr/local/Cellar/elixir-ls/language_server.sh
(finished - exit code 1) ['/bin/zsh', '-c', 'cd ''.'' && mix help credo && mix credo suggest --format=flycheck --read-from-stdin ''/Users/landon/Desktop/example.ex'' < ''/var/folders/mt/4fyz36kj69l0j5fffrwlsvdh0000gn/T/nvimyUeVyq/6/example.ex''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', 'cd ''.'' && mix help dialyzer && mix dialyzer < ''/var/folders/mt/4fyz36kj69l0j5fffrwlsvdh0000gn/T/nvimyUeVyq/7/example.ex''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', 'cd ''.'' && mix help credo && mix credo suggest --format=flycheck --read-from-stdin ''/Users/landon/Desktop/example.ex'' < ''/var/folders/mt/4fyz36kj69l0j5fffrwlsvdh0000gn/T/nvimyUeVyq/8/example.ex''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', 'cd ''.'' && mix help dialyzer && mix dialyzer < ''/var/folders/mt/4fyz36kj69l0j5fffrwlsvdh0000gn/T/nvimyUeVyq/9/example.ex''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', 'cd ''.'' && mix help credo && mix credo suggest --format=flycheck --read-from-stdin ''/Users/landon/Desktop/example.ex'' < ''/var/folders/mt/4fyz36kj69l0j5fffrwlsvdh0000gn/T/nvimyUeVyq/10/example.ex''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', 'cd ''.'' && mix help dialyzer && mix dialyzer < ''/var/folders/mt/4fyz36kj69l0j5fffrwlsvdh0000gn/T/nvimyUeVyq/11/example.ex''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', 'cd ''.'' && mix help credo && mix credo suggest --format=flycheck --read-from-stdin ''/Users/landon/Desktop/example.ex'' < ''/var/folders/mt/4fyz36kj69l0j5fffrwlsvdh0000gn/T/nvimyUeVyq/12/example.ex''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', 'cd ''.'' && mix help dialyzer && mix dialyzer < ''/var/folders/mt/4fyz36kj69l0j5fffrwlsvdh0000gn/T/nvimyUeVyq/13/example.ex''']

<<>>

```