[3.11] gh-114275: Skip doctests that use `asyncio` in `test_pdb` for WASI builds (GH-114309) (#114438)

gh-114275: Skip doctests that use `asyncio` in `test_pdb` for WASI builds (GH-114309)
(cherry picked from commit efb81a60f5ce7e192095230a0f7ff9684d6f835a)

Co-authored-by: Nikita Sobolev <mail@sobolevn.me>