kakoune-lsp: use replaceVars

-        fi

         echo >$kak_command_fifo "echo -to-file $kak_response_fifo -quoting kakoune -- %reg{a}"

-        perl < $kak_response_fifo -we '

+        @perl@ < $kak_response_fifo -we '

+        @perl@/bin/perl < $kak_response_fifo -we '

             use strict;

             my $Q = "'\''";

             my @args = ();

     set-register x nop

     evaluate-commands %sh[ # $kak_quoted_selections

-        perl -e '

+        @perl@ -e '

+        @perl@/bin/perl -e '

 use strict;

 use warnings;

 use Text::ParseWords();

  lib,

  rustPlatform,

  fetchFromGitHub,

  substituteAll,

  replaceVars,

  perl,

  stdenv,

  CoreServices,

    sha256 = "sha256-uXKquAjfytUn/Q0kx+0BGRQTkVMQ9rMRnTCy622upag=";

  };

  patches = [

    (substituteAll {

      src = ./Hardcode-perl.patch;

      perl = lib.getExe perl;

    })

  ];

  patches = [ (replaceVars ./Hardcode-perl.patch { inherit perl; }) ];

  cargoHash = "sha256-XnhYODMzqInwbgM8wveY048sljZ8OKw4hLYJG5h8Twc=";