update amd_macos for cross compilation (#530)

Since CircleCI no longer supports intel mac agents, use the apple
silicon and cross compile

---------

Co-authored-by: ApolloBot2 <support@apollographql.com>

.circleci/config.yml

@@ -184,9 +184,10 @@ executors:
   amd_macos: &amd_macos_executor
     macos:
       xcode: "14.2"
-    resource_class: macos.x86.medium.gen2
+    resource_class: macos.m1.large.gen1
     environment:
       XTASK_TARGET: "x86_64-apple-darwin"
+      RUSTUP_TARGET: "x86_64-apple-darwin" # cross-compile, because there are no native x86 macos runners
       APPLE_TEAM_ID: "YQK948L752"
       APPLE_USERNAME: "opensource@apollographql.com"
       MACOS_PRIMARY_BUNDLE_ID: com.apollographql.supergraph