Target the Python 3.10 limited API, not 3.8.

dev-python/cython-3.3 refuses to generate limited-API code below 3.9, so the
generated wrapper fails to compile outright:

  build/tilelang_cython_wrapper.cpp:70:8: error:
    #error "Cython 3.3 requires the Python Limited API version to be 3.9 or greater."

The cp38 target is upstream's own inconsistency rather than a real constraint:
the same pyproject.toml declares requires-python = ">=3.10", so the package
cannot run on 3.8 or 3.9 anyway, and this ebuild only builds for
PYTHON_COMPAT=( python3_{12..14} ). cp310 matches the declared floor and
satisfies Cython.

wheel.py-api feeds SKBUILD_SABI_VERSION, which CMakeLists.txt passes to
python_add_library() as USE_SABI -- that is what becomes -DPy_LIMITED_API.
verified 2026-08-31 against 0.1.12; the same one-line change as 0.1.13.
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -93,7 +93,7 @@
 build-backend = "scikit_build_core.build"
 
 [tool.scikit-build]
-wheel.py-api = "cp38"
+wheel.py-api = "cp310"
 cmake.version = ">=3.26.1"
 build-dir = "build"