commit 8ee20ec introduces a conflict with rustaceanvim

## Information

**VIM version**

NVIM v0.10.4
Build type: Release

Operating System: Ubuntu 24.04.2 LTS, MacOS 15.3.2 (reproduces on both)

## What went wrong

Commit 8ee20ec changes the way LSPs are set up. For Rust, rustaceanvim requires special handling (see the warning [here](https://github.com/mrcjkb/rustaceanvim?tab=readme-ov-file#zap-quick-setup)). This commit conflicts with rustaceanvim and causes the rust-analyzer to be loaded twice, resulting in errors such other plugins being unable to attach to the LSP on Rust files. (The immediately prior commit, f3512cd, does not exhibit this behaviour.)

## Reproducing the bug

1. Install ale (at a commit prior to 8ee20ec).
2. Install and set up rustaceanvim.
3. Install other Rust plugins.
3. Open a Rust source file. Observe that everything works correctly.
4. Update ale (past commit 8ee20ec).
5. Open a Rust source file. Observe that Rust plugins are broken due to rust-analyzer being loaded twice.

### :ALEInfo

Expand
Current Filetype:
Available Linters: []
Enabled Linters: []
Ignored Linters: []
Suggested Fixers:
'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.

Global Variables:
" Press Space to read :help for a setting
let g:ale_cache_executable_check_failures = v:null
let g:ale_change_sign_column_color = v:null
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 = 'auto'
let g:ale_echo_cursor = 1
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 = {}
let g:ale_history_enabled = 1
let g:ale_info_default_mode = 'preview'
let g:ale_history_log_output = 1
let g:ale_keep_list_window_open = v:null
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 = {}
let g:ale_linters_explicit = 0
let g:ale_linters_ignore = {}
let g:ale_list_vertical = v:null
let g:ale_list_window_size = v:null
let g:ale_loclist_msg_format = v:null
let g:ale_max_buffer_history_size = v:null
let g:ale_max_signs = v:null
let g:ale_maximum_file_size = v:null
let g:ale_open_list = v:null
let g:ale_pattern_options = {'.*\.java$': {'ale_enabled': 0}}
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 = v:null
let g:ale_sign_error = v:null
let g:ale_sign_info = v:null
let g:ale_sign_offset = v:null
let g:ale_sign_style_error = v:null
let g:ale_sign_style_warning = v:null
let g:ale_sign_warning = v:null
let g:ale_sign_highlight_linenrs = v:null
let g:ale_type_map = v:null
let g:ale_use_neovim_diagnostics_api = 1
let g:ale_use_global_executables = v:null
let g:ale_virtualtext_cursor = 'all'
let g:ale_warn_about_trailing_blank_lines = 1
let g:ale_warn_about_trailing_whitespace = 1

Command History: