[mono] Use C11 atomics in atomic.h when building with MSVC

[lambdageek]

There are two things we need to do:

1. Pass the /experimental:c11atomics to the MSVC compiler for the runtime build
2. Use C++23 when building our C++ files (they may include "atomic.h" which includes <stdatomic.h> which errors out in MSVC in C++ mode unless you're using at least C++23)

Tagging subscribers to this area: @dotnet/area-infrastructure-libraries
See info in area-owners.md if you want to be subscribed.

Issue Details

---

There are two things we need to do:

1. Pass the /experimental:c11atomics to the MSVC compiler for the runtime build
2. Use C++23 when building our C++ files (they may include "atomic.h" which includes <stdatomic.h> which errors out in MSVC in C++ mode unless you're using at least C++23)

Author:	lambdageek
Assignees:	-
Labels:	area-Infrastructure-libraries
Milestone:	-

Tagging subscribers to this area: @directhex
See info in area-owners.md if you want to be subscribed.

Issue Details

---

There are two things we need to do:

1. Pass the /experimental:c11atomics to the MSVC compiler for the runtime build
2. Use C++23 when building our C++ files (they may include "atomic.h" which includes <stdatomic.h> which errors out in MSVC in C++ mode unless you're using at least C++23)

Author:	lambdageek
Assignees:	-
Labels:	area-Infrastructure-mono
Milestone:	-

[lambdageek]

Follow-up for #90404