ci(docker): update cmake to 3.15.2

GitOrigin-RevId: f704ca38542434028474d564a4bf688e2daa7973

CMakeLists.txt

-cmake_minimum_required(VERSION 3.14.4)
+cmake_minimum_required(VERSION 3.15.2)
 
 include (cmake/FetchMegBrainVersion.cmake)
 project(MegEngine LANGUAGES C CXX VERSION ${MGB_VER_STRING})

scripts/cmake-build/BUILD_README.md

@@ -39,7 +39,7 @@
     ```
 ### linux host build
     ```
-    1: cmake, which version > 3.14.4
+    1: cmake, which version > 3.15.2
     2: gcc/g++, which version > 6, (gcc/g++ >= 7, if need build training)
     3: install build-essential git git-lfs gfortran libgfortran-6-dev autoconf gnupg flex bison gperf curl 
     4: zlib1g-dev gcc-multilib g++-multilib lib32ncurses5-dev libxml2-utils xsltproc unzip libtool:
@@ -48,7 +48,7 @@
     ```
 ### macos host build
     ```
-    1: cmake, which version > 3.14.4
+    1: cmake, which version > 3.15.2
     2: install brew: /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
     3: brew install python python3 swig coreutils
     4: install at least xcode command line tool: https://developer.apple.com/xcode/

scripts/whl/macos/macos_whl_env_prepare.sh

@@ -74,12 +74,12 @@ function install_cmake() {
             mkdir -p ${CMAKE_INSTALL_DIR}
         fi
 
-        rm -rf ${CMAKE_INSTALL_DIR}/src/cmake-3.14.4.tar.gz
+        rm -rf ${CMAKE_INSTALL_DIR}/src/cmake-3.15.2.tar.gz
         mkdir ${CMAKE_INSTALL_DIR}/src
         cd ${CMAKE_INSTALL_DIR}/src
-        wget https://cmake.org/files/v3.14/cmake-3.14.4.tar.gz
-        tar -xvf cmake-3.14.4.tar.gz
-        cd cmake-3.14.4
+        wget https://cmake.org/files/v3.15/cmake-3.15.2.tar.gz
+        tar -xvf cmake-3.15.2.tar.gz
+        cd cmake-3.15.2
         mkdir build
         cd build
         ../configure --prefix=${CMAKE_INSTALL_DIR}/install