Update release.yaml

Make darwin_amd64 explicit

Author: achew22

.github/workflows/release.yaml

@@ -36,7 +36,8 @@ jobs:
             artifact: ibazel_darwin_amd64
             os: macos-latest
             build_flags: --platforms=@io_bazel_rules_go//go/toolchain:darwin_amd64_cgo
-            cpu_flag:
+            # See comment below for more information on this flag.
+            cpu_flag: --cpu=darwin_amd64
             ext: ""
 
           - name: darwin_arm64