relxExe: remove

relxExe is not intended to be used as a single standalone executable, but as a library by rebar3

pkgs/development/beam-modules/default.nix

···
       # without helper functions buildRebar3 and buildMix.
       hex = callPackage ./hex { };
       webdriver = callPackage ./webdriver { };
-      relxExe = callPackage ../tools/erlang/relx-exe { };
     };
 in
 makeExtensible packages

pkgs/development/tools/erlang/relx-exe/default.nix

···
-{ fetchHex, fetchRebar3Deps, rebar3Relx }:
-
-rebar3Relx rec {
-  name = "relx-exe";
-  version = "4.3.0";
-  releaseType = "escript";
-
-  src = fetchHex {
-    pkg = "relx";
-    sha256 = "sha256-c44JSab8fQ3p5FSdwPc9m24FtTnhURuySFkHArMiBEA=";
-    inherit version;
-  };
-
-  checkouts = fetchRebar3Deps {
-    inherit name version;
-    src = "${src}/rebar.lock";
-    sha256 = "sha256-BY/c4+vqdnn4FBPzLExEZIZ27f1g46XISb8mIpMU8aI=";
-  };
-}

pkgs/top-level/all-packages.nix

···
   inherit (beam.packages.erlang)
     erlang-ls
     rebar rebar3 rebar3WithPlugins
-    fetchHex beamPackages
-    relxExe;
+    fetchHex beamPackages;
 
   inherit (beam.packages.erlangR21) lfe lfe_1_3;