stdenv/darwin: fix for curl with zstd and idn2

The `curlMinimal` is to be used throughout the early bootstrap
stages. The final stage will allow the new references of the `curl`.

Fixes: 29526bc2 ('curl: IDN support requires libidn2 package')

pkgs/stdenv/darwin/default.nix

@@ -399,6 +399,8 @@ rec {
       persistent = self: super: with prevStage; {
         cmake = super.cmakeMinimal;
 
+        curl = super.curlMinimal;
+
         inherit pbzx cpio;
 
         python3 = super.python3Minimal;
@@ -755,6 +757,9 @@ rec {
         darwin.binutils
         darwin.binutils.bintools
         curl.out
+        zstd.out
+        libidn2.out
+        libunistring.out
         openssl.out
         libssh2.out
         nghttp2.lib