ci: windows: Stop using DEBUG:FASTLINK

ci: windows: Stop using DEBUG:FASTLINK

Currently the pdb file for libpq and some other libraries are named the same
for the static and shared libraries. That has been the case for a long time,
but recently started failing, after an image update started using a newer
ninja version. The issue is not itself caused by ninja, but just made visible,
as the newer version optimizes the build order and builds the shared libpq
earlier than the static library. Previously both static and shared libraries
were built at the same time, which prevented msvc from detecting the issue.

When using /DEBUG:FASTLINK pdb files cannot be updated, triggering the error.

We were using /DEBUG:FASTLINK due to running out of memory in the past, but
that was when using container based CI images, rather than full VMs.

This isn't really the correct fix (that'd be to deconflict the pdb file
names), but we'd like to get CI to become green again, and a proper fix (in
meson) will presumably take longer.

Suggested-by: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAN55FZ1RuBhJmPWs3Oi%3D9UoezDfrtO-VaU67db5%2B0_uy19uF%2BA%40mail.gmail.com
Backpatch-through: 16