Moving pragma for MSVC warning C4505 from pybind11.h to existing list in detail/common.h (#3160)

* Moving pragma for C4505 from pybind11.h to existing list in detail/common.h.

* Removing 4 existing suppressions to 1. see what is still needed and 2. capture the MSVC messages.

* It turns out none of the 4 pragmas are needed anymore.

include/pybind11/detail/common.h

@@ -135,7 +135,8 @@
 #    define HAVE_ROUND 1
 #  endif
 #  pragma warning(push)
-#  pragma warning(disable: 4510 4610 4512 4005)
+// C4505: 'PySlice_GetIndicesEx': unreferenced local function has been removed (PyPy only)
+#  pragma warning(disable: 4505)
 #  if defined(_DEBUG) && !defined(Py_DEBUG)
 #    define PYBIND11_DEBUG_MARKER
 #    undef _DEBUG

include/pybind11/pybind11.h

@@ -13,7 +13,6 @@
 #if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #  pragma warning(push)
 #  pragma warning(disable: 4127) // warning C4127: Conditional expression is constant
-#  pragma warning(disable: 4505) // warning C4505: 'PySlice_GetIndicesEx': unreferenced local function has been removed (PyPy only)
 #elif defined(__GNUG__) && !defined(__clang__) && !defined(__INTEL_COMPILER)
 #  pragma GCC diagnostic push
 #  pragma GCC diagnostic ignored "-Wunused-but-set-parameter"