Stop spamming logs if plenary fails to spawn curl

[VoxelPrismatic]

This turns this error message:

Error executing vim.schedule lua callback: .../.local/share/nvim/lazy/plenary.nvim/lua/plenary/job.lua:406: Failed to spaw
  _additional_on_exit_callbacks = {},
  _shutdown_check = <userdata 1>,
  _stderr_results = {},
  _stdout_results = {},
  _user_on_exit = <function 1>,
  args = { "-sSL", "-D", "/run/user/1000/plenary_curl_bc5048ce.headers", "-X", "POST", "-H", "Content-Type: application/json", "ua_dXDQAJ", "http://127.0.0.1:40309/exa.language_server_pb.LanguageServerService/Heartbeat" },
  command = "curl",
  enable_handlers = true,
  enable_recording = true,
  interactive = true,
  pid = "EMFILE: too many open files",
  stderr = <userdata 2>,
  stdin = <userdata 3>,
  stdout = <userdata 4>,
  user_data = {},
  <metatable> = <1>{
    __index = <table 1>,
    _create_uv_options = <function 2>,
    _execute = <function 3>,
    _pipes_are_closed = <function 4>,
    _prepare_pipes = <function 5>,
    _reset = <function 6>,
    _shutdown = <function 7>,
    _stop = <function 8>,
    add_on_exit_callback = <function 9>,
    after = <function 10>,
    after_failure = <function 11>,
    after_success = <function 12>,
    and_then = <function 13>,
    and_then_on_failure = <function 14>,
    and_then_on_failure_wrap = <function 15>,
    and_then_on_success = <function 16>,
    and_then_on_success_wrap = <function 17>,
    and_then_wrap = <function 18>,
    chain = <function 19>,
    chain_status = <function 20>,
    co_wait = <function 21>,
    is_job = <function 22>,
    join = <function 23>,
    new = <function 24>,
    pid = <function 25>,
    result = <function 26>,
    send = <function 27>,
    shutdown = <function 28>,
    start = <function 29>,
    stderr_result = <function 30>,
    sync = <function 31>,
    wait = <function 32>
  }
}
stack traceback:
        .../.local/share/nvim/lazy/plenary.nvim/lua/plenary/job.lua:406: in function '_execute'
        .../.local/share/nvim/lazy/plenary.nvim/lua/plenary/job.lua:449: in function 'start'
        ....local/share/nvim/lazy/plenary.nvim/lua/plenary/curl.lua:323: in function 'post'
        ...z/.local/share/nvim/lazy/codeium.nvim/lua/codeium/io.lua:440: in function 'post'
        .../.local/share/nvim/lazy/codeium.nvim/lua/codeium/api.lua:172: in function 'request'
        .../.local/share/nvim/lazy/codeium.nvim/lua/codeium/api.lua:179: in function 'do_heartbeat'
        .../.local/share/nvim/lazy/codeium.nvim/lua/codeium/api.lua:316: in function ''
        vim/_editor.lua: in function <vim/_editor.lua:0>
stack traceback:
        [C]: in function 'error'
        .../.local/share/nvim/lazy/plenary.nvim/lua/plenary/job.lua:406: in function '_execute'
        .../.local/share/nvim/lazy/plenary.nvim/lua/plenary/job.lua:449: in function 'start'
        ....local/share/nvim/lazy/plenary.nvim/lua/plenary/curl.lua:323: in function 'post'
        ...z/.local/share/nvim/lazy/codeium.nvim/lua/codeium/io.lua:440: in function 'post'
        .../.local/share/nvim/lazy/codeium.nvim/lua/codeium/api.lua:172: in function 'request'
        .../.local/share/nvim/lazy/codeium.nvim/lua/codeium/api.lua:179: in function 'do_heartbeat'
        .../.local/share/nvim/lazy/codeium.nvim/lua/codeium/api.lua:316: in function ''

In to:

Failed to spawn curl: EMFILE: too many open files

This way, Plenary stops spamming the error logs should curl fail to spawn. Without this change, Neovim would hang on quit because it now has to parse thousands of error messages and pipe them into the scroller.

[CLAassistant]

All committers have signed the CLA.

[VoxelPrismatic]

Solves #292
Solves #290