Force fetching x64 zap for mac even on arm. (#26747)

* Force fetching x64 zap for mac even on arm.

Apparently arm64 version of zap was pulled.
Rosetta can run x64 just fine, so start
using that instead.

* Update scripts/setup/zap.json

Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>

* Update scripts/setup/zap.json

Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>

* Update scripts/setup/zap.json

Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>

* Restyled by prettier-json

---------

Co-authored-by: Andrei Litvin <andreilitvin@google.com>
Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>
Co-authored-by: Restyled.io <commits@restyled.io>

scripts/setup/zap.json

@@ -6,10 +6,15 @@
                 "linux-amd64",
                 "linux-arm64",
                 "mac-amd64",
-                "mac-arm64",
                 "windows-amd64"
             ],
             "tags": ["version:2@v2023.05.22-nightly.1"]
+        },
+        {
+            "_comment": "Always get the amd64 version on mac until usable arm64 zap build is available",
+            "path": "fuchsia/third_party/zap/mac-amd64",
+            "platforms": ["mac-arm64"],
+            "tags": ["version:2@v2023.05.22-nightly.1"]
         }
     ]
 }