[Backtracing] Don't use the hardened runtime for tests.

Using the hardened runtime for tests doesn't work.

rdar://107362003

utils/swift-darwin-postprocess.py

@@ -92,7 +92,7 @@ def unrpathize(filename):
 def codesign(filename):
     # "-" is the signing identity for ad-hoc signing.
     command = ['/usr/bin/codesign', '--force', '--sign', '-',
-               '--options=runtime', '--entitlements', get_task_allow_plist,
+               '--entitlements', get_task_allow_plist,
                filename]
     subprocess.check_call(command)