Automatically add protobuf_MSVC_STATIC_RUNTIME=OFF when protobuf_BUILD_SHARED_LIBS=OFF

[ahoarau]

What version of protobuf and what language are you using?
Version: 26.x
Language: C++

What operating system (Linux, Windows, ...) and version?
Windows
What runtime / compiler are you using (e.g., python version or gcc version)
msvc 2022
What did you do?

Buid protobuf as a static library.

cmake -S protobuf -B protobuf-build-release -G Ninja  -Dprotobuf_BUILD_SHARED_LIBS=OFF

Then link against some static library, you will get errors like this:

libcpmtd.lib(xstol.obj) : error LNK2038: mismatch detected for 'RuntimeLibrary': value 'MTd_StaticDebug' doesn't match value 'MDd_DynamicDebug' in cmake_pch.cxx.obj

It is fixed by passing -Dprotobuf_MSVC_STATIC_RUNTIME=OFF to the cmake configure args.

Is there any reason why protobuf_MSVC_STATIC_RUNTIME is not OFF by default when protobuf_BUILD_SHARED_LIBS=OFF ?

For package management, it would be great.