Merge topic 'cmake-use-findpython'

313ea361b0 CMake: Use FindPython instead of FindPythonInterp to build CMake itself
b6a6190877 string(): Support hash functions in bootstrap

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !7197