Remove ntree limit in python package. (#8345)

- Remove `ntree_limit`. The parameter has been deprecated since 1.4.0.
- The SHAP package compatibility is broken.

tests/ci_build/conda_env/aarch64_test.yml

@@ -31,6 +31,5 @@ dependencies:
 - pyspark
 - cloudpickle
 - pip:
-  - shap
   - awscli
   - auditwheel

tests/ci_build/conda_env/linux_cpu_test.yml

@@ -37,7 +37,6 @@ dependencies:
 - pyarrow
 - protobuf
 - cloudpickle
-- shap>=0.41
 - modin
 # TODO: Replace it with pyspark>=3.4 once 3.4 released.
 # - https://ml-team-public-read.s3.us-west-2.amazonaws.com/pyspark-3.4.0.dev0.tar.gz

tests/ci_build/lint_python.py

@@ -146,6 +146,7 @@ def main(args: argparse.Namespace) -> None:
                 "tests/python/test_config.py",
                 "tests/python/test_data_iterator.py",
                 "tests/python/test_dt.py",
+                "tests/python/test_predict.py",
                 "tests/python/test_quantile_dmatrix.py",
                 "tests/python/test_tree_regularization.py",
                 "tests/python-gpu/test_gpu_data_iterator.py",