- setup-win32: drop duplicate `WIN32_LEAN_AND_MEAN` and `NOGDI` macros
(set earlier in `curl_setup.h`)
- config-win32ce: detect ARM for `CURL_OS` macro.
Based on: https://cegcc.sourceforge.net/docs/details.html
It should also apply to MSVC. (untested)
- indentation.
Closes#16029