qt_internal_generate_tool_command_wrapper might fail to generate wrapper script due to unrelated configuration failure

qt_internal_generate_tool_command_wrapper in QtBuild.cmake is supposed to generate a qt_setup_tool_path.bat file whenver QtBuild.cmake is included.

Note that it has an early return if QT_TOOL_COMMAND_WRAPPER_PATH set.
We set QT_TOOL_COMMAND_WRAPPER_PATH on the first call and then call file(GENERATE).
But the file(GENERATE) might fail if an unrelated configuration error happens, and yet QT_TOOL_COMMAND_WRAPPER_PATH would already be set.

So reconfiguring would not try to recreate the file.

We should improve this somehow, perhaps by removing the early return, if that does not cause needless command rerunning because the file might be regenerated with different contents.