Add script for change version. (#8443)

- Replace jvm regex replacement script with mvn command.
- Replace cmake script for python version with python script.
- Automate rest of the manual steps.

The script can handle dev branch, rc release, and formal release version.

cmake/Python_version.in

@@ -1 +0,0 @@
-@xgboost_VERSION_MAJOR@.@xgboost_VERSION_MINOR@.@xgboost_VERSION_PATCH@-dev

cmake/Version.cmake

@@ -3,7 +3,4 @@ function (write_version)
   configure_file(
     ${xgboost_SOURCE_DIR}/cmake/version_config.h.in
     ${xgboost_SOURCE_DIR}/include/xgboost/version_config.h @ONLY)
-  configure_file(
-    ${xgboost_SOURCE_DIR}/cmake/Python_version.in
-    ${xgboost_SOURCE_DIR}/python-package/xgboost/VERSION @ONLY)
 endfunction (write_version)