ibmcloud-cli: drop x86_64-darwin from update script

pkgs/by-name/ib/ibmcloud-cli/package.nix

@@ -21,13 +21,7 @@ let
       "s390x"
     else
       throw "Unsupported arch: ${stdenv.hostPlatform.system}";
-  platform =
-    if stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64 then
-      "macos_arm64"
-    else if stdenv.hostPlatform.isDarwin then
-      "macos"
-    else
-      "linux_${arch}";
+  platform = if stdenv.hostPlatform.isDarwin then "macos_arm64" else "linux_${arch}";
 in
 stdenv.mkDerivation (finalAttrs: {
   pname = "ibmcloud-cli";

pkgs/by-name/ib/ibmcloud-cli/update.sh

@@ -19,7 +19,6 @@ for system in \
     i686-linux \
     powerpc64le-linux \
     s390x-linux \
-    x86_64-darwin \
     aarch64-darwin; do
     tmp=$(mktemp -d)
     curl -fsSL -o $tmp/ibmcloud-cli $(nix-instantiate --eval -E "with import ./. {}; ibmcloud-cli.src.url" --system "$system" | tr -d '"')