Merge bitcoin/bitcoin#30731: build: remove old MSVC build system

04fb085 build: remove old MSVC build system (fanquake)

Pull request description:

  This has been superseded by CMake, and should not be blocked on anything for removal.

ACKs for top commit:
  laanwj:
    ACK 04fb085
  hebasto:
    ACK 04fb085.
  TheCharlatan:
    ACK 04fb085
  vasild:
    ACK 04fb085, except:

Tree-SHA512: 219005bd0de1a9e37dabe45c979601df3083368f4c5ea224f70cf4e6f52e49d8f25713015ce005be3b34b56377eaafa339be7c50c63ce7f3ce7841ae55f3221f

Author: fanquake