What cmake commands are run? I was unable to reproduce. The following Powershell commands worked for me:
# Define path to CMake:
$cmake='C:\Program Files\CMake\bin\cmake.exe'
# Get C driver 1.25.0:
git clone https://github.com/mongodb/mongo-c-driver --branch 1.25.0
cd mongo-c-driver
# Configure:
& "$cmake" -G "Visual Studio 16 2019" -A x64 `
-DCMAKE_INSTALL_PREFIX="C:\mongo-c-driver-1.25.0" `
-S. -Bcmake-build
# Build and install:
& "$cmake" --build cmake-build --target INSTALL