which linter is used

[xyecoding]

I enabled no linter.
Texlive auto installs 'chktex' and 'lacheck' together. I removed both of them. However, some linters are still used.
I do not have any of ['alex', 'chktex', 'cspell', 'lacheck', 'proselint', 'redpen', 'texlab', 'textlint', 'vale', 'writegood'] on my computer.
Here is a screen in which warnings are reported and some hinter must be used.

here is my ALEInFo

 Current Filetype: tex
Available Linters: ['alex', 'chktex', 'cspell', 'lacheck', 'proselint', 'redpen', 'texlab', 'textlint', 'vale', 'writegood']
   Linter Aliases:
'writegood' -> ['write-good']
  Enabled Linters: []
  Ignored Linters: []
 Suggested Fixers: 
  'latexindent' - Indent code within environments, commands, after headings and within special code blocks.
  'remove_trailing_lines' - Remove all blank lines at the end of a file.
  'textlint' - Fix text files with textlint --fix
  'trim_whitespace' - Remove all trailing whitespace characters at the end of every line.
 Linter Variables:

 Global Variables:

let g:ale_cache_executable_check_failures = v:null
let g:ale_change_sign_column_color = 0
let g:ale_command_wrapper = v:null
let g:ale_completion_delay = v:null
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 = 1
let g:ale_echo_msg_error_str = 'E'
let g:ale_echo_msg_format = '%code: %%s'
let g:ale_echo_msg_info_str = 'Info'
let g:ale_echo_msg_warning_str = 'W'
let g:ale_enabled = 1
let g:ale_fix_on_save = 0
let g:ale_fixers = {}
let b:ale_fixers = ['prettier', '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 = 0
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 = 'never'
let g:ale_linter_aliases = {}
let g:ale_linters = {'go': ['go', 'golint', 'errcheck'], 'tex': [], 'javascript': ['eslint'], 'python': ['flake8']}
let g:ale_linters_explicit = 1
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 = v:null
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 = 0
let g:ale_set_loclist = 1
let g:ale_set_quickfix = 0
let g:ale_set_signs = 1
let g:ale_sign_column_always = 1
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:

[pbnj]

In your screenshot, below the statusline, it shows [coc.nvim] Texlab Server Started.

I suggest you start looking there.