Help/cmake-cxxmodules: drop "preview" release of Visual Studio

The final release is out; no need to mention prerelease versions.

Help/manual/cmake-cxxmodules.7.rst

@@ -81,8 +81,7 @@ Support for ``import std`` is limited to the following toolchain and standard
 library combinations:
 
 * Clang 18.1.2 and newer with ``-stdlib=libc++`` or ``-stdlib=libstdc++``
-* MSVC toolset 14.36 and newer (provided with Visual Studio 17.6 Preview 2 and
-  newer)
+* MSVC toolset 14.36 and newer (provided with Visual Studio 17.6 and newer)
 * GCC 15 and newer
 
 The :variable:`CMAKE_CXX_COMPILER_IMPORT_STD` variable lists standard levels