[breaking] Bump Python requirement to 3.10. (#10434)

- Bump the Python requirement.
- Fix type hints.
- Use loky to avoid deadlock.
- Workaround cupy-numpy compatibility issue on Windows caused by the `safe` casting rule.
- Simplify the repartitioning logic to avoid dask errors.

tests/ci_build/Dockerfile.gpu

@@ -27,7 +27,8 @@ RUN \
         "nccl>=${NCCL_SHORT_VER}" \
         dask \
         dask-cuda=$RAPIDS_VERSION_ARG* dask-cudf=$RAPIDS_VERSION_ARG* cupy \
-        numpy pytest pytest-timeout scipy scikit-learn pandas matplotlib wheel python-kubernetes urllib3 graphviz hypothesis \
+        numpy pytest pytest-timeout scipy scikit-learn pandas matplotlib wheel \
+        python-kubernetes urllib3 graphviz hypothesis loky \
         "pyspark>=3.4.0" cloudpickle cuda-python && \
     mamba clean --all --yes && \
     conda run --no-capture-output -n gpu_test pip install buildkite-test-collector

tests/ci_build/Dockerfile.gpu_dev_ver

@@ -30,7 +30,8 @@ RUN \
         "nccl>=${NCCL_SHORT_VER}" \
         dask \
         "dask-cuda=$RAPIDS_VERSION_ARG.*" "dask-cudf=$RAPIDS_VERSION_ARG.*" cupy \
-        numpy pytest pytest-timeout scipy scikit-learn pandas matplotlib wheel python-kubernetes urllib3 graphviz hypothesis \
+        numpy pytest pytest-timeout scipy scikit-learn pandas matplotlib wheel \
+        python-kubernetes urllib3 graphviz hypothesis loky \
         "pyspark>=3.4.0" cloudpickle cuda-python && \
     mamba clean --all --yes && \
     conda run --no-capture-output -n gpu_test pip install buildkite-test-collector

tests/ci_build/conda_env/aarch64_test.yml

@@ -2,7 +2,7 @@ name: aarch64_test
 channels:
 - conda-forge
 dependencies:
-- python=3.8
+- python=3.10
 - pip
 - wheel
 - pytest
@@ -26,7 +26,7 @@ dependencies:
 - awscli
 - numba
 - llvmlite
-- cffi
+- loky
 - pyarrow
 - pyspark>=3.4.0
 - cloudpickle

tests/ci_build/conda_env/linux_cpu_test.yml

@@ -2,7 +2,7 @@ name: linux_cpu_test
 channels:
 - conda-forge
 dependencies:
-- python=3.8
+- python=3.10
 - cmake
 - c-compiler
 - cxx-compiler
@@ -33,7 +33,7 @@ dependencies:
 - boto3
 - awscli
 - py-ubjson
-- cffi
+- loky
 - pyarrow
 - protobuf
 - cloudpickle

tests/ci_build/conda_env/linux_sycl_test.yml

@@ -3,7 +3,7 @@ channels:
 - conda-forge
 - https://software.repos.intel.com/python/conda/
 dependencies:
-- python=3.8
+- python=3.10
 - cmake
 - c-compiler
 - cxx-compiler

tests/ci_build/conda_env/macos_cpu_test.yml

@@ -2,7 +2,7 @@ name: macos_test
 channels:
 - conda-forge
 dependencies:
-- python=3.8
+- python=3.10
 - pip
 - wheel
 - pyyaml
@@ -32,7 +32,7 @@ dependencies:
 - jsonschema
 - boto3
 - awscli
-- cffi
+- loky
 - pyarrow
 - pyspark>=3.4.0
 - cloudpickle

tests/ci_build/conda_env/python_lint.yml

@@ -2,11 +2,11 @@ name: python_lint
 channels:
 - conda-forge
 dependencies:
-- python=3.8
+- python=3.10
 - pylint<3.2.4  # https://github.com/pylint-dev/pylint/issues/9751
 - wheel
 - setuptools
-- mypy>=0.981
+- mypy
 - numpy
 - scipy
 - pandas

tests/ci_build/conda_env/sdist_test.yml

@@ -3,7 +3,7 @@ name: sdist_test
 channels:
 - conda-forge
 dependencies:
-- python=3.8
+- python=3.10
 - pip
 - wheel
 - cmake

tests/ci_build/conda_env/win64_cpu_test.yml

@@ -2,7 +2,7 @@ name: win64_env
 channels:
 - conda-forge
 dependencies:
-- python=3.8
+- python=3.10
 - wheel
 - numpy
 - scipy
@@ -18,5 +18,5 @@ dependencies:
 - python-graphviz
 - pip
 - py-ubjson
-- cffi
+- loky
 - pyarrow

tests/ci_build/conda_env/win64_test.yml

@@ -2,7 +2,7 @@ name: win64_env
 channels:
 - conda-forge
 dependencies:
-- python=3.8
+- python=3.10
 - numpy
 - scipy
 - matplotlib
@@ -12,9 +12,9 @@ dependencies:
 - boto3
 - hypothesis
 - jsonschema
-- cupy
+- cupy>=13.2
 - python-graphviz
 - pip
 - py-ubjson
-- cffi
+- loky
 - pyarrow