test: xfail case insensitive regex tests for cuDF

[LiamConnors]

What type of PR is this? (check all applicable)

• 💾 Refactor
• ✨ Feature
• 🐛 Bug Fix
• 🔧 Optimization
• 📝 Documentation
• ✅ Test
• 🐳 Other

Related issues

• Related issue # test: Get all cuDF tests passing #862
• Closes #

Checklist

• Code follows style guide (ruff)
• Tests added
• Documented the changes

If you have comments or can explain your changes, please do so below.

These tests fail with a runtime error:

FAILED tests/expr_and_series/str/contains_test.py::test_contains[cudf_constructor] - RuntimeError: CUDF failure at:/opt/conda/conda-bld/work/cpp/src/strings/reg...

What I can find is that (?i) is likely not supported for cuDF. That's what it sounds like from rapidsai/cudf#5217 (the issue was opened for str.replace).

[FBruzzesi]

Thanks @LiamConnors 🙌🏼

Would it be worth adding a test for the case sensitive case to see if that passes as a follow up?

[LiamConnors]

Thanks @FBruzzesi! That's a good idea. I'll open a PR for it.