[CI] Support CMake 4.0 (#11382)

* [CI] Use gtest from conda.

* check version.

* don't use conda gtest.

* debug.

* Try using dmlc/dmlc-core#690

* Add back aarch64_test.yml

* Use C++14 for gtest

* Require C++14 for gtest when found by find_package

* Require C++14 everywhere in dmlc-core

* Lower gtest requirement to 1.14

* Update dmlc-core

---------

Co-authored-by: Hyunsu Cho <phcho@nvidia.com>

Author: trivialfis

dmlc-core

@@ -3,7 +3,7 @@ channels:
 - conda-forge
 dependencies:
 - python=3.10
-- cmake
+- cmake>=3.26.4
 - c-compiler
 - cxx-compiler
 - ninja

ops/conda_env/linux_cpu_test.yml

@@ -4,7 +4,7 @@ channels:
 - https://software.repos.intel.com/python/conda/
 dependencies:
 - python=3.10
-- cmake
+- cmake>=3.26.4
 - c-compiler
 - cxx-compiler
 - pip

ops/conda_env/linux_sycl_test.yml

@@ -9,6 +9,7 @@ source activate aarch64_test
 echo "--- Build libxgboost from the source"
 mkdir -p build
 pushd build
+
 cmake .. \
   -GNinja \
   -DCMAKE_PREFIX_PATH="${CONDA_PREFIX}" \