Move ARM64 Windows to stable tier-2

[zware]

No description provided.

[zware]

I'm a bit hesitant to add this one to the stable set, as it tends to follow a cycle:

• restart
• run fine for N days
• start running out of memory during compile
• crash, requiring reboot from the hypervisor
• fail test_os.TestScandir.test_attributes (see traceback below)
• goto 10

This is what we have, though, and AFAICT this is intrinsic to the platform rather than there being anything particular to this worker that causes it. It will just take some vigilance on my part to keep it going until such time as we (or the MS compiler team) find something to fix more permanently.

test_os.TestScandir.test_attributes failure:

======================================================================
FAIL: test_attributes (test.test_os.test_os.TestScandir.test_attributes)
----------------------------------------------------------------------
Traceback (most recent call last):
File "C:\Users\buildworker\buildarea\3.x.ware-win11-arm64.nondebug\build\Lib\test\test_os\test_os.py", line 5037, in test_attributes
self.check_entry(entry, 'dir', True, False, False)
~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\buildworker\buildarea\3.x.ware-win11-arm64.nondebug\build\Lib\test\test_os\test_os.py", line 5005, in check_entry
self.assert_stat_equal(entry.stat(),
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^
entry_stat,
^^^^^^^^^^^
os.name == 'nt' and not is_symlink)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\buildworker\buildarea\3.x.ware-win11-arm64.nondebug\build\Lib\test\test_os\test_os.py", line 4964, in assert_stat_equal
self.assertEqual(getattr(stat1, attr),
~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
getattr(stat2, attr),
^^^^^^^^^^^^^^^^^^^^^
(stat1, stat2, attr))
^^^^^^^^^^^^^^^^^^^^^
AssertionError: 16 != 268435472 : (os.stat_result(st_mode=16895, st_ino=0, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0, st_atime=1785263657, st_mtime=1785263657, st_ctime=1785263657), os.stat_result(st_mode=16895, st_ino=1036109389272253500, st_dev=6923181900724247706, st_nlink=1, st_uid=0, st_gid=0, st_size=0, st_atime=1785263657, st_mtime=1785263657, st_ctime=1785263657), 'st_file_attributes')

Note that restarting the system tends to fix this, but sometimes it takes an extra restart. I do not have any idea why that fixes it.

[encukou]

Sounds reasonable to me.

Tiers require reliable buildbots, so calling this behaviour unreliable while promoting ARM/Windows to T2 would be somewhat inconsistent :)