Remove Windows 32 bit build
The win32 target will no longer be part of our release nor officially
It is still possible for users to run the build by themselves, but the
instructions are removed from the doc in order to reflect the
"unsupported" status of this target.
Backport of core PR15939.
Depends on D5610.
Run the Windows Gitian build. Check the win32 binaries are no longer
part of the output.
Reviewers: #bitcoin_abc, jasonbcox
Reviewed By: #bitcoin_abc, jasonbcox
Differential Revision: https://reviews.bitcoinabc.org/D5612