opam-repository: remove broken/unnecessary patch

pkgs/development/ocaml-modules/opam-repository/default.nix

@@ -10,12 +10,6 @@ buildDunePackage {
 
   inherit (opam-format) src version;
 
-  patches = [ ./download-tool.patch ];
-  postPatch = ''
-    substituteInPlace src/repository/opamRepositoryConfig.ml \
-      --replace-fail "SUBSTITUTE_NIXOS_CURL_PATH" "\"${curl}/bin/curl\""
-  '';
-
   propagatedBuildInputs = [ opam-format ];
 
   configureFlags = [ "--disable-checks" ];

pkgs/development/ocaml-modules/opam-repository/download-tool.patch

@@ -1,37 +0,0 @@
-diff --git a/src/repository/opamRepositoryConfig.ml b/src/repository/opamRepositoryConfig.ml
-index c2954c1d..528fc621 100644
---- a/src/repository/opamRepositoryConfig.ml
-+++ b/src/repository/opamRepositoryConfig.ml
-@@ -27,31 +27,7 @@ type 'a options_fun =
-   'a
- 
- let default = {
--  download_tool = lazy (
--    let os = OpamStd.Sys.os () in
--    try
--      let curl = "curl", `Curl in
--      let tools =
--        match os with
--        | Darwin  -> ["wget", `Default; curl]
--        | FreeBSD -> ["fetch", `Default ; curl]
--        | OpenBSD -> ["ftp", `Default; curl]
--        | _ -> [curl; "wget", `Default]
--      in
--      let cmd, kind =
--        List.find (fun (c,_) -> OpamSystem.resolve_command c <> None) tools
--      in
--      [ CIdent cmd, None ], kind
--    with Not_found ->
--      OpamConsole.error_and_exit `Configuration_error
--        "Could not find a suitable download command. Please make sure you \
--         have %s installed, or specify a custom command through variable \
--         OPAMFETCH."
--        (match os with
--         | FreeBSD -> "fetch"
--         | OpenBSD -> "ftp"
--         | _ -> "either \"curl\" or \"wget\"")
--  );
-+  download_tool = lazy ([ CIdent SUBSTITUTE_NIXOS_CURL_PATH, None ], `Curl);
-   validation_hook = None;
-   retries = 3;
-   force_checksums = None;