Increase tolerance in TestGARCH11::test_batched_size to reduce flakiness

[JigyasuRajput]

Description

Increased the absolute (atol=1e-3) and relative (rtol=1e-2) tolerances in np.testing.assert_allclose within TestGARCH11::test_batched_size.
This should help reduce test flakiness caused by minor numerical variations.

Related Issue

• Closes Flaky tests/distributions/test_timeseries.py::TestGARCH11::test_batched_size #7674

Checklist

• Checked that the pre-commit linting/style checks pass
• Included tests that prove the fix is effective or that the new feature works (ran pytest tests/distributions/test_timeseries.py)
• Added necessary documentation (docstrings and/or example notebooks)
• If you are a pro: each commit corresponds to a relevant logical change

Type of change

• Bug fix
• New feature / enhancement
• Documentation
• Maintenance
• Other (please specify):

---

📚 Documentation preview 📚: https://pymc--7684.org.readthedocs.build/en/7684/

[welcome]

]
💖 Thanks for opening this pull request! 💖 The PyMC community really appreciates your time and effort to contribute to the project. Please make sure you have read our Contributing Guidelines and filled in our pull request template to the best of your ability.

[ricardoV94]

Hmm looks like that test should be deterministic, so the failures may indicate an underlying bug. Can you check if the results come different in different runs of the test?