ALEEnable/ALEToggle does not enable ALE in all buffers/splits

## Information

```
NVIM v0.5.0-dev+nightly-298-g0a653f7ab
Build type: Release
```
OR
```
VIM - Vi IMproved 8.2 (2019 Dec 12, compiled May 26 2021 20:32:10)
macOS version - arm64
Included patches: 1-2890
```

Operating System: macOS 11.4 BigSur arm64

## What went wrong

ALEEnable/ALEToggle does not enable ALE in all buffers.

## Reproducing the bug

1. Enable ALE by default, so it starts upon launch.
2. Open two vertical splits.
3. Make sure both the window shave some ALE warning/error signs visible in sign column.
4. Run ``:ALEToggle``, this will hide warning/error signs from all splits.
5. Run ``:ALEToggle`` or ``:ALEEnable``, this will only show the warning/error signs in the buffer that was last visited/focussed (i.e where the cursor will go back after running the command).

### :ALEInfo

```

Current Filetype: lua
Available Linters: ['luac', 'luacheck']
Enabled Linters: ['luac', 'luacheck']
Ignored Linters: []
Suggested Fixers:
'luafmt' - Fix Lua files with luafmt.
'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_lua_luac_executable = 'luac'
let g:ale_lua_luacheck_executable = 'luacheck'
let g:ale_lua_luacheck_options = ''
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 = 0
let g:ale_completion_enabled = 0
let g:ale_completion_max_suggestions = v:null
let g:ale_disable_lsp = 1
let g:ale_echo_cursor = 0
let g:ale_echo_msg_error_str = 'Error'
let g:ale_echo_msg_format = v:null
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 = 0
let g:ale_fixers = {'verilog': ['verible-verilog-format']}
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 = 0
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 = {'verilog': ['verible', 'iverilog'], 'python': ['pylint']}
let g:ale_linters_explicit = 0
let g:ale_linters_ignore = {}
let g:ale_list_vertical = 0
let g:ale_list_window_size = 10
let g:ale_loclist_msg_format = '%code: %%s'
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_root = {}
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 = 1
let g:ale_warn_about_trailing_blank_lines = 1
let g:ale_warn_about_trailing_whitespace = 1
Command History:

(executable check - success) luac
(finished - exit code 0) ['/bin/zsh', '-c', '''luac'' -p - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/6/wezterm.lua''']

<<>>

(executable check - success) luacheck
(finished - exit code 1) ['/bin/zsh', '-c', '''luacheck'' --formatter plain --codes --filename ''/Users/reportaman/.config/wezterm/wezterm.lua'' - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/7/wezterm.lua''']

<<>>

(finished - exit code 0) ['/bin/zsh', '-c', '''luac'' -p - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/8/wezterm.lua''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', '''luacheck'' --formatter plain --codes --filename ''/Users/reportaman/.config/wezterm/wezterm.lua'' - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/9/wezterm.lua''']

<<>>

(finished - exit code 0) ['/bin/zsh', '-c', '''luac'' -p - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/11/wezterm.lua''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', '''luacheck'' --formatter plain --codes --filename ''/Users/reportaman/.config/wezterm/wezterm.lua'' - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/12/wezterm.lua''']

<<>>

(finished - exit code 0) ['/bin/zsh', '-c', '''luac'' -p - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/14/wezterm.lua''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', '''luacheck'' --formatter plain --codes --filename ''/Users/reportaman/.config/wezterm/wezterm.lua'' - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/15/wezterm.lua''']

<<>>

(finished - exit code 0) ['/bin/zsh', '-c', '''luac'' -p - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/17/wezterm.lua''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', '''luacheck'' --formatter plain --codes --filename ''/Users/reportaman/.config/wezterm/wezterm.lua'' - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/18/wezterm.lua''']

<<>>

(finished - exit code 1) ['/bin/zsh', '-c', '''luac'' -p - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/20/wezterm.lua''']

<<>>
luac: stdin:11: expected near '='
<<>>

(finished - exit code 1) ['/bin/zsh', '-c', '''luacheck'' --formatter plain --codes --filename ''/Users/reportaman/.config/wezterm/wezterm.lua'' - < ''/var/folders/40/g1hxt47j5sn3wg34689bfpnr0000gn/T/nvimzzcLGx/21/wezterm.lua''']

<<>>

```