chore(windows): remove addins can cherry pick commit ⛏️

Addins can be removed, and this commit [5f07f7](https://github.com/keymanapp/keyman/pull/8593/commits/5f07f7ad080991bd9f2feebec0d9cc261be107c5)can be cherry picked however the UNI_CHAR hook message should not be advanced to the next message. It can be removed with #8677

_Originally posted by @rc-swag in https://github.com/keymanapp/keyman/issues/8593#issuecomment-1524755613_
            