test_timerfd_initval fails with large time difference on NetBSD

Bug report

Bug description:

The test_timerfd_initval test in test_os.TimerfdTests is failing on NetBSD with a very large time difference between the expected and actual expiration values. The test expects values to be almost equal within 3 decimal places, but the actual difference is over 1.7 billion seconds.

Configuration:

./configure --with-pydebug

Test

./python -m test test_os -m test_timerfd_initval -v

Output:

== CPython 3.14.0a6+ (heads/main:26511993e63, Mar 15 2025, 01:30:33) [GCC 10.5.0]
== NetBSD-10.0-amd64-x86_64-64bit-ELF little-endian
== Python build: debug
== cwd: /home/blue/cpython/build/test_python_worker_20567æ
== CPU count: 16
== encodings: locale=UTF-8 FS=utf-8
== resources: all test resources are disabled, use -u option to unskip tests
Using random seed: 3011250179
0:00:00 load avg: 2.25 Run 1 test sequentially in a single process
0:00:00 load avg: 2.25 [1/1] test_os
test_timerfd_initval (test.test_os.TimerfdTests.test_timerfd_initval) ... FAIL
======================================================================
FAIL: test_timerfd_initval (test.test_os.TimerfdTests.test_timerfd_initval)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/blue/cpython/Lib/test/test_os.py", line 4327, in test_timerfd_initval
    self.assertAlmostEqual(next_expiration, initial_expiration, places=self.CLOCK_RES_PLACES)
    ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 1741991497.5326333 != 0.25 within 3 places (1741991497.2826333 difference)
----------------------------------------------------------------------
Ran 1 test in 0.010s
FAILED (failures=1)
test test_os failed
0:00:00 load avg: 2.25 [1/1/1] test_os failed (1 failure)
== Tests result: FAILURE ==
1 test failed:
    test_os
Total duration: 958 ms
Total tests: run=1 (filtered) failures=1
Total test files: run=1/1 (filtered) failed=1
Result: FAILURE

OS: NetBSD-10.0-amd64

CPython versions tested on:

CPython main branch, 3.14, 3.13

Operating systems tested on:

Other

Bắt đầu với Lib/test/test_os.py và TimerfdTests.test_timerfd_initval, sau đó chạy ./python -m test test_os -m test_timerfd_initval -v trên NetBSD với cấu hình được báo cáo. So sánh các giá trị hết hạn của bộ hẹn giờ dự kiến và thực tế, đồng thời điều tra hành vi dành riêng cho NetBSD; hoàn tất khi bài kiểm thử chạy đạt chính xác trên nền tảng bị ảnh hưởng.