gh-138573: filter out failing math tests on Solaris

[skirpichev]

• Issue: test.test_math.MathTests.testAtan2 failure on OpenIndiana/Solaris #138573

[vstinner]

I can see the test_math.testAtan2() and test_cmath.test_phase() failures on the Solaris buildbot: https://buildbot.python.org/#/builders/742/builds/9890

ERROR: testAtan2 (test.test_math.MathTests.testAtan2)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/var/share/buildbot-worker/python/3.x.kulikjak-solaris-sparcv9/build/Lib/test/test_math.py", line 306, in testAtan2
    self.ftest('atan2(0., -0.)', math.atan2(0., -0.), math.pi)
                                 ~~~~~~~~~~^^^^^^^^^
ValueError: math domain error

and

ERROR: test_phase (test.test_cmath.CMathTests.test_phase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/var/share/buildbot-worker/python/3.x.kulikjak-solaris-sparcv9/build/Lib/test/test_cmath.py", line 410, in test_phase
    self.assertAlmostEqual(phase(0), 0.)
                           ~~~~~^^^
ValueError: math domain error

[vstinner]

There are the two same errors on the 3.14 Solaris buildbot: https://buildbot.python.org/#/builders/1804/builds/808. So we can backport this change to 3.14.

On the 3.13 Solaris buildbot, test_math and test_cmath pass, so there is no need to backport to 3.13.

[miss-islington-app]

Thanks @skirpichev for the PR, and @vstinner for merging it 🌮🎉.. I'm working now to backport this PR to: 3.14.
🐍🍒⛏🤖

[bedevere-app]

GH-146438 is a backport of this pull request to the 3.14 branch.