Fix MSVC MT/MD incompatibility in PYBIND11_BUILD_ABI (#4953)

* Fix MSVC MT/MD incompatibility in PYBIND11_BUILD_ABI

* Update comment about which PR

* Use msvc major version

* Use _MSC_VER/100

* Fix figuring out MD vs MT

* Add some test runs

* Skip one test

* Fix preprocessor

* simplify code

* fix if

* support only msvc 19

* Fold in changes from experimental PR #5411. Polish error messages.

* Remove `&& defined(_DLL)` (TBD: is it needed? but what is correct?)

* Fix MT vs MD

* Add a couple comments, based on https://github.com/pybind/pybind11/pull/4953#issuecomment-2435138593 (posted by @isuruf).

* Replace misleading comment: NVHPC is NOT outdated.

* Update include/pybind11/detail/internals.h

Co-authored-by: Robert Maynard <robertjmaynard@gmail.com>

---------

Co-authored-by: Ralf W. Grosse-Kunstleve <rgrossekunst@nvidia.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rwgkio@gmail.com>
Co-authored-by: Robert Maynard <robertjmaynard@gmail.com>

.github/workflows/ci.yml

@@ -65,6 +65,24 @@ jobs:
           # Inject a couple Windows 2019 runs
           - runs-on: windows-2019
             python: '3.9'
+          # Inject a few runs with different runtime libraries
+          - runs-on: windows-2022
+            python: '3.9'
+            args: >
+              -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded
+          - runs-on: windows-2022
+            python: '3.10'
+            args: >
+              -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDLL
+          # This needs a python built with MTd
+          # - runs-on: windows-2022
+          #   python: '3.11'
+          #   args: >
+          #     -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDebug
+          - runs-on: windows-2022
+            python: '3.12'
+            args: >
+              -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDebugDLL
           # Extra ubuntu latest job
           - runs-on: ubuntu-latest
             python: '3.11'