Help: CXX_STANDARD 26 is supported on some compilers

e.g.  80d4bd5 added CXX_STANDARD 26 to IntelLLVM

Help/prop_tgt/CXX_STANDARD.rst

@@ -40,9 +40,6 @@ Supported values are:
 ``26``
   .. versionadded:: 3.25
 
-  C++26. CMake 3.25 and later *recognize* ``26`` as a valid value,
-  no version has support for any compiler.
-
 If the value requested does not result in a compile flag being added for
 the compiler in use, a previous standard flag will be added instead.  This
 means that using: