Revert "[CMake][NewPM] Move ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER into llvm/"

The new pass manager was accidentally enabled by default with this change.

This reverts commit a36bd4c90dcca82be9b64f65dbd22e921b6485ef.

GitOrigin-RevId: 806a76c001233f2c70bf93c73fb955c64c1c080f
7 files changed