No Safari experimental run since January 14

[jrobbins]

No successful Safari experimental run since January 14 (wpt.fyi view).

@gsnedders could you take a look?

[Loirooriol]

The Azure pipelines in PRs are also broken, e.g. https://dev.azure.com/web-platform-tests/wpt/_build/results?buildId=132251&view=logs&j=bf8f5026-3d1f-5955-26be-17f9e1ef0bb3&t=f2f2a672-3250-5564-df22-32ed9c3bfd05

ERROR WebDriver was not accessible within 30 seconds.
ERROR Traceback (most recent call last):
 File "/Users/runner/work/1/s/tools/wptrunner/wptrunner/browsers/base.py", line 373, in _run_server
   wait_for_service(
 File "/Users/runner/work/1/s/tools/wptrunner/wptrunner/environment.py", line 377, in wait_for_service
   raise OSError("Service is unavailable: %s:%i" % addr)
OSError: Service is unavailable: 127.0.0.1:49309

ERROR Failure during init:
Traceback (most recent call last):
 File "/Users/runner/work/1/s/tools/wptrunner/wptrunner/testrunner.py", line 261, in init
   self.browser.start(group_metadata=group_metadata, **self.browser_settings)
 File "/Users/runner/work/1/s/tools/wptrunner/wptrunner/browsers/base.py", line 339, in start
   self._run_server(group_metadata, **kwargs)
 File "/Users/runner/work/1/s/tools/wptrunner/wptrunner/browsers/base.py", line 373, in _run_server
   wait_for_service(
 File "/Users/runner/work/1/s/tools/wptrunner/wptrunner/environment.py", line 377, in wait_for_service
   raise OSError("Service is unavailable: %s:%i" % addr)
OSError: Service is unavailable: 127.0.0.1:49309