Remove mac arm64 workaround from test runner. NFC (#25736)

See #25730

Author: sbc100

test/runner.py

@@ -25,7 +25,6 @@
 import math
 import operator
 import os
-import platform
 import random
 import sys
 import time
@@ -420,9 +419,7 @@ def run_tests(options, suites):
     print('Test suites:', [s[0] for s in suites])
   # Run the discovered tests
 
-  # We currently don't support xmlrunner on macOS M1 runner since
-  # `pip` doesn't seeem to yet have pre-built binaries for M1.
-  if os.getenv('CI') and not (utils.MACOS and platform.machine() == 'arm64'):
+  if os.getenv('CI'):
     os.makedirs('out', exist_ok=True)
     # output fd must remain open until after testRunner.run() below
     output = open('out/test-results.xml', 'wb')