run-crate: Always use x64 tarballs for mac

There are no aarch64/arm64 distributions for CrateDB for Mac, so this
changes the URL pattern to use the x64 version instead which should work
via the emulation layer

cr8/run_crate.py

@@ -58,21 +58,26 @@ class ReleaseUrlSegments(NamedTuple):
     @classmethod
     def create(cls):
         extension = 'tar.gz'
+
+        machine = platform.machine()
+        if machine.startswith('arm'):
+            arch = 'aarch64'
+        else:
+            arch = 'x64'
+
         if sys.platform.startswith('linux'):
             os = 'linux'
         elif sys.platform.startswith('win32'):
             os = 'windows'
             extension = 'zip'
         elif sys.platform.startswith('darwin'):
             os = 'mac'
-        else:
-            raise ValueError(f'Unsupported platform: {sys.platform}')
 
-        machine = platform.machine()
-        if machine.startswith('arm'):
-            arch = 'aarch64'
-        else:
+            # there are no aarch64/arm64 distributions available
+            # x64 should work via emulation layer
             arch = 'x64'
+        else:
+            raise ValueError(f'Unsupported platform: {sys.platform}')
 
         return ReleaseUrlSegments(arch=arch, os=os, extension=extension)